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  • Rat  (288)
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  • Springer  (354)
  • 1970-1974  (354)
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  • 1
    ISSN: 1432-0738
    Keywords: Alcohol, Ethyl ; Absorption ; Elimination ; Alcohol Oxidoreductases ; Hepatitis, Toxic ; Transaminases ; Glutamate Dehydrogenase ; Guinea Pig ; Rat ; Äthylalkohol ; Resorption ; Elimination ; Alkoholdehydrogenase ; Hepatotoxicität ; Transaminasen ; Glutamatdehydrogenase ; Meerschweinchen ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die maximalen Blutalkoholkonzentrationen nach oraler Gabe von 6,4 g/kg Äthanol in Form einer 40%igen Lösung (v/v) betrugen bei nicht nüchternen Meerschweinchen 6,8±0,3 mg/ml, bei nicht nüchternen Ratten dagegen nur 2,1±0,2 mg/ml. An nüchternen Tieren führte eine orale Alkoholbelastung von 4,8 g/kg zu maximalen Blutalkoholspiegeln von 6,3±0,2 mg/ml bei den Meerschweinchen und 3,7±0,3 mg/ml bei den Ratten. Intravenös injizierter Alkohol (1 g/kg) wurde demgegenüber von beiden Species mit der gleichen Geschwindigkeit eliminiert (275 mg/kg · Std), und die auf das Körpergewicht bezogene ADH-Aktivität der Leber war bei den Meerschweinchen um 20% größer als bei den Ratten. Die Resorption von Äthanol erfolgt somit bei Ratten erheblich langsamer als bei Meerschweinchen. Dies dürfte darauf beruhen, daß konzentrierte Alkohollösungen die Magenentleerung der Ratte stark verzögern. Niedriger konzentrierte Alkohollösungen werden von der Ratte schneller resorbiert; jedoch waren auch nach Gabe von 10%igem Alkohol die maximalen Blutalkoholspiegel bei Ratten noch um 36% niedriger als bei Meerschweinchen. Bei den Meerschweinchen waren nach oraler Gabe von 4,8 bzw. 6,4 g/kg Äthanol die Serumaktivitäten der GOT, GPT und GLDH erhöht; ein Anstieg der SGOT trat schon nach 1,6 g/kg Äthanol auf. Demgegenüber kam es bei Ratten nach 6,4 g pro kg Äthanol p.o. nur zu geringfügigen Aktivitätserhöhungen der Serumtransaminasen, während die Serumaktivität der GLDH unverändert blieb. Vacuolige Degeneration war das morphologische Substrat der durch Äthanol bei Meerschweinchen und Ratten ausgelösten Leberschädigung. Während diese Veränderung bei Meerschweinchen bereits nach einer Äthanoldosis von 1,6 g/kg auftrat, wurde sie bei Ratten erst nach 6,4 g/kg beobachtet. Schlußfolgerung: Das Meerschweinchen ist für Untersuchungen zur Toxicität von Äthanol besser geeignet als die Ratte.
    Notes: Abstract In fed guinea pigs, an oral dose of 6.4 g/kg of ethanol given as a 40% solution (v/v) produced a maximal blood alcohol level of 6.8±0.3 mg/ml, whereas in fed rats, blood alcohol levels after the same dose did not exceed 2.1±0.2 mg/ml. Maximal blood alcohol levels in fasted animals after an oral load of 4.8 g/kg of ethanol were 6.3±0.2 mg/ml in guinea pigs and 3.7±0.3 mg/ml for rats. However, i.v. injected ethanol (1 g/kg) was eliminated at the same rate in both species (275 mg per kg · h), and ADH activity of the liver related to body weight was by 20% greater in guinea pigs than in rats. Therefore, absorption of ethanol occurs at a much slower rate in rats than in guinea pigs. This is possibly due to the fact that high ethanol concentrations strongly delay emptying of the rat stomach. Lowering the ethanol concentration accelerates absorption rate in the rat. However, even after gavage of a 10% solution peak levels of blood alcohol were still lower by 36% in rats than in guinea pigs. In guinea pigs, increased serum activities of GOT, GPT, and GLDH occurred after an oral dose of 4.8 g/kg or 6.4 g/kg of ethanol, respectively. SGOT already increased after 1.6 g/kg of ethanol p.o. After 6.4 g/kg of ethanol given to rats serum transaminase levels increased only slightly, and GLDH activity not at all. Vacuolar degeneration was the morphological substrate of ethanol-induced liver damage in guinea pigs and rats. In guinea-pigs, it occurred already after 1.6 g/kg of ethanol, whereas in rats only after 6.4 g/kg. In conclusion, the guinea pig seems to be better suited for research on alcohol toxicity than the rat.
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  • 2
    ISSN: 1432-1106
    Keywords: Locus ceruleus ; Cerulo-cortical tract ; Ascending reticular fiber ; Rat ; Fink-Heimer method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to demonstrate the ascending projection from the locus ceruleus by degeneration silver method, the nucleus was destroyed unilaterally in rats and the brains were stained by a modified Fink-Heimer method following various survival times. Additional experiments included the bilateral destruction of the locus ceruleus and the administration of 6-OH-DOPA. For the demonstration of degenerated terminals in the cerebral cortex it is essential to choose an optimal survival time of 4 or 5 days, keep the time of fixation below 1 week, and perform treatments with permanganate and with silver at 37°C. The trajectory and distribution of the cerulo-cortical tract as revealed by the silver degeneration methods is in agreement with the results of the histofluorescence method, with some minor differences. The ascending fibers run through Forel's tegmental fascicle, turn rostro-ventrally to the subthalamus, enter and cross the internal capsule, pass through the ventral part of the caudate-putamen and distribute to the entire cerebral cortex. The tract is mainly ipsilateral, though some fibers are crossing.
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  • 3
    ISSN: 1432-1106
    Keywords: Preoptic units ; Thermosensitivity ; Mean firing rate ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mean firing rates (per 10 sec) of preoptic neurons of the rat were recorded at normal temperature and after central warming and cooling. Thermosensitivity was determined according to the reactions of the mean firing rate. In compatibility with results from other animals we obtained the following percentages (52 neurons): 23% warm-sensitive, 13% cold-sensitive, 64% non-thermosensitive neurons. However, it turned out that a lot of interesting special effects are not taken into account, using exclusively the criterion “increasing/decreasing/constant mean firing rate”. Particularly we observed long lasting adaption processes and stationary non-linear effects as well as striking oscillations which were dependent on the thermal stimuli, while the mean interval value remained constant.
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  • 4
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    Electronic Resource
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    Research in experimental medicine 163 (1974), S. 341-349 
    ISSN: 1433-8580
    Keywords: Experimental uremic syndrome ; Rat ; 5/6 reduction of renal parenchyma ; Serum- and urine analysis ; Secondary hyperparathyroidism ; Experimentelles urämisches Syndrom ; Ratte ; 5/6-Reduktion des Nierenparenchyms ; Serum- und Urinanalyse ; Sekundärer Hyperparathyreoidismus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Durch eine 5/6-Nierenparenchymreduktion wurde an Ratten ein chronisches, durch bilaterale Nephrektomie ein akutes urämisches Syndrom erzeugt. Beim chronischen urämischen Syndrom erwiesen sich in der Serumanalyse die Konzentrationen des Harnstoffstickstoffs und des Kreatinins als wesentlich erhöht. Darüber hinaus bestanden alle chemischen Zeichen eines sekundären Hyperparathyreoidismus. Die Tiere litten außerdem an einer schweren Poly-, Protein- und Albuminurie. Überraschenderweise war aber der Spiegel des totalen Serumproteins gegenüber den Kontrolltieren erhöht. Das experimentelle chronische urämische Syndrom stellt eine extreme Adaptation der regulatorischen Aktivität des Nierenrestparenchyms und des ganzen Organismus dar. Beim akuten, durch bilaterale Nephrektomie erzeugten urämischen Syndrom besteht dagegen ein schweres Versagen der Regulation des Wasser- und Elektrolytstoffwechsels, welches innert 50–60 Std zum Tode der Versuchstiere führt.
    Notes: Summary A chronic uremic syndrome was induced by 5/6 nephrectomy and an acute uremic syndrome by bilateral nephrectomy in rats. In the chronic uremic syndrome serum and urine analysis revealed a highly increased serum level of BUN and creatinine. Furthermore, all chemical signs typical of secondary hyperparathyroidism were present. The animals suffered from severe polyuria, protein- and albuminuria but, surprisingly, the total serum protein was increased. The experimental chronic uremic syndrome is, in essence, a syndrome of “extreme adaptation” of the regulatory activity of remnant renal parenchyma and of the whole body. In contrast, the acute uremic syndrome induced by bilateral nephrectomy is a severe disorder of water and electrolyte metabolism resulting in death of the experimental animals after 50–60 hrs.
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  • 5
    ISSN: 1433-8580
    Keywords: Gastrinpentapeptide ; Vagotomy ; Acid secretion ; Perfusion test ; Rat ; Gastrinpentapeptid ; Vagotomie ; Säuresekretion ; Perfusionsversuch ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei männlichen Wistarratten wurde eine trunkuläre beiderseitige Vagotomie — ergänzt durch eine Pyloroplastik — angelegt. 4 Wochen später erfolgte in Urethannarkose eine Perfusion des Magens mit 0,9%iger NaCl-Lösung in Anlehnung an die Versuchsanordnung von Ghosh. Die Vollständigkeit der Vagotomie bestätigte ein Hypoglykämietest. Im Abstand von 150 min erhielten die Tiere — in 6 Gruppen zu je 10 Ratten — 2 × 50, 100, 150, 200, 250 oder 300 µg/kg KG Pentagastrin subcutan. Die statistisch ausgewerteten Ergebnisse lassen sich wie folgt zusammenfassen: 1. Die nach dem Abklingen der Wirkung der ersten Pentagastrininjektion wiederholte Pentagastringabe in derselben Dosis ergab bei allen Dosierungen eine höhere Säuresekretion als nach der ersten Injektion. 2. Ein Maximum der sezernierten Säuremenge wurde bei einer Dosis von 100 µg/kg KG erreicht. Bei höherer Dosierung des Pentagastrins nahm die Menge der sezernierten Säure signifikant ab.
    Notes: Summary Male Wistar rats were subjected to a complete bilateral vagotomy and a pyloroplasty. 4 weeks later followed in urethane anesthesia a continuous perfusion of the stomach with 0.9% saline according to the rat preparation of Ghosh. The completeness of the gastric vagotomy was confirmed by a postoperative insulin test. In an interval of 150 min the rats — in 6 groups of 10 rats each — were two times injected pentagastrin subcutaneously in dose rates of 50, 100, 150, 250 or 300 µg/kg body weight. The statistical confirmed results can be summarized as followed: 1. The second injection of pentagastrin — 150 min after the first — in the same dose produced a significantly higher gastric acid secretion in the rat all dose rates in comparison to the first injection. 2. The maximal gastric acid secretion was produced by a dose rate of 100 µg/kg body weight of pentagastrin. At higher dose rates of pentagastrin there was a significant reduction of gastric acid secretion.
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  • 6
    ISSN: 1433-8580
    Keywords: Kidney ; Rat ; Ultrastructure ; Proximal tubule degeneration ; Heparinoid ; Niere ; Ratte ; Ultrastruktur ; Proximale Tubulusdegeneration ; Heparinoid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 24 Std nach i.v. Injektion von 100 mg/kg eines Pentosanschwefelsäureesters (SP 54) sind in der Nierenrinde von Ratten schwere degenerative Veränderungen der proximalen Tubuluszellen zu beobachten. Das Tubulusepithel ist flachkubisch umgewandelt, das Tubuluslumen ist angefüllt mit ausgestoßenen Mitochondrien und anderen Zelltrümmern. Am stärksten betroffen ist die Pars contorta des proximalen Tubulus. Weniger stark veränderte Tubuluszellen sind angefüllt mit Cytosomen, die eine spezifische Feinstruktur haben oder gehäuft gegenüber Kontrollen Cytoplasmaprotrusionen in das Tubuluslumen aufweisen. Die akute Tubulusdegeneration ist ein spezifischer Effekt von SP 54. Heparin bewirkt nur eine leichte Schwellung des Tubulusepithels, die häufiger auftritt als bei Kontrolltieren.
    Notes: Summary 24 hrs after the intravenous injection of 100 mg/kg of a Pentosansulfuricacidester (SP 54) severe degenerative alterations are observed in the proximal tubular cells in rat kidney cortex. The tubular epithelium has changed to a single layer of elongated cubic cells. The tubular lumen is filled with cellular debris and extruded mitochondria. The greatest change is seen in the pars contorta of the proximal tubule. Less degenerated tubular cells have a great number of cytosomes with a specific substructure or have cytoplasmatic protrusions into the tubular lumen. This acute tubular degeneration is a specific event after the administration of SP 54 and is not seen after an equimolar dosis of Heparin. Heparin induces only a slight swelling of the tubular epithelium, more frequent seen as in the control animals.
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  • 7
    ISSN: 1432-0568
    Keywords: Superior cervical ganglion ; Rat ; p-Chlorophenylalanine ; 5-Hydroxytryptamine ; Catecholamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Wirkung von Parachlorophenylalanin (pCPA) auf die paraganglionären Zellen und sympathischen Ganglienzellen des Ganglion cervicale superius der Ratte wurde untersucht. pCPA beeinflußt die sympathischen Nervenzellen im Ganglion cervicale superius geringgradig. Es finden sich unspezifische Veränderungen des Golgi-Apparates und der Nissl-Schollen sowie eine Zunahme von Lysosomen. Bei langdauernder Behandlung degenerieren einzelne Ganglienzellen und Nervenfasern. Die paraganglionären Zellen sind bei Kontrolltieren durch “dense core vesicles” eines einheitlichen Typs charakterisiert. Im Laufe der pCPA-Behandlung finden sich degranulierte paraganglionäre Zellen. Die Degranulation der einzelnen Zellelemente ist jedoch variabel. Bei fluorescenzmikroskopischer Untersuchung zeigt sich nach pCPA-Applikation eine Verschiebung des Fluorescenzspektrums zum grünen Bereich hin. Die bei Kontrollen deutliche Gelbkomponente nimmt nach 6–12 Tagen ab und verschwindet schließlich nach 18–20 Tagen. Es wird diskutiert, ob die fluorescenzmikroskopischen Veränderungen aufgrund einer Hemmung der Serotoninsynthese oder aufgrund einer abgeschwächten Katecholaminsynthese entstehen.
    Notes: Summary The effect of parachlorophenylalanine (pCPA) on the paraganglionic and sympathetic nerve cells of the rat superior cervical ganglion was studied. pCPA influences the sympathetic nerve cells of the cervical ganglion to minimal extent. Unspecific changes of the Golgi apparatus and of the Nissl bodies as well as an increase in the number of lysosomes occur. An extended period of treatment causes degeneration of individual ganglionic cells and nerve fibers. The paraganglionic cells in control animals are characterized by dense core vesicles of an unitary type. During pCPA treatment degranulated paraganglionic cells are to be found. The degranulation of the individual cell elements varies. Fluorescence microscopic study after pCPA application shows a shift of the fluorescence spectrum toward green. The yellow component of the control group decreases after 6 to 12 days and disappears after 18 or 20 days. It is discussed whether the fluorescence microscopic changes are due to the inhibition of serotonine synthesis or to a decrease of the catecholamine synthesis.
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  • 8
    ISSN: 1432-0568
    Keywords: Median eminence ; Neuro-vascular contacts ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The vascular surface of the external layer of the median eminence is composed of neuronal and glial processes. Neuro-vascular contacts are supposed to be necessary for the release of hypophysiotropic neurohormones. The present study confirms the hypothesis that the relative extent of neuro-vascular and glio-vascular contacts varies under different functional conditions of the tubero-hypophysial system. Morphometric analysis shows that in normal rats about 20% of the surface is lined by neuro-vascular contacts. After bilateral adrenalectomy the neuro-vascular contacts are enlarged to 40% whereas application of an extract of stalk-median eminence tissue is followed by a decrease of the neuro-vascular contacts to 15%. The implications of these results are discussed.
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  • 9
    ISSN: 1432-0568
    Keywords: X zone ; Electron microscopy ; Development ; Adrenal ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The postnatal development and involution of the X zone in the mouse adrenal cortex of both sexes were examined using the light and electron microscopes. At 0–5 days of age, no special cell group could be distinguished for the developing X zone in the inner cortex. The inner cortical cells contained spherical or ellipsoidal mitochondria with vesiculotubular cristae, vesiculotubular smooth endoplasmic reticulum (sER) and electron-lucent lipid droplets. The first sign of the developing X zone was the appearance of small groups of cells in juxtamedullary region differing from the cells in other part of inner cortex at 8 days. The electron microscopy showed that such cells contained nuclei of somewhat irregular outline and some parallel stacks of flattened sER. At 10–11 days, a thin layer of small eosinophilic cells were clearly identified as the developing X zone light microscopically in both sexes. Electron microscopically, the X zone cells showed a much dense cytoplas, which contained abundant sER, many mitochondria and numerous ribosomes. The typical X zone cells were characterized by the formation of peculiar mitochondrial complexes and whorled pattern of the sER. Mitoses were often found in the X zone, where mitotic cells even contained the whorled sER and bizarre mitochondria characteristic of the typical X zone cells. In the male the X zone rapidly involuted and might disappear by 30 days of age, whereas in the female X zone persisted as a thicker layer with the earlist sign of fatty degeneration. The origin of the X zone cell and the process of formation of its characteristic organelles are discussed.
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  • 10
    ISSN: 1432-0568
    Keywords: Subcommissural organ ; Periodically structured bodies ; Vascular permeability ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Capillaren des Subcommissuralorgans (SCO) und deren Umgebung wurden an 38 adulten Sprague-Dawley- und an 6 adulten Wistar-Ratten nach Perfusionsfixierung im Elektronenmikroskop untersucht. Saure Mucopolysaccharide wurden mit Alcianblau und Rutheniumrot, Glykoproteide mittels der Perjodsäure-Silbermethenamin-Reaktion nachgewiesen. Der Stofftransport in den Capillaren wurde mit Meerrettichperoxidase (MRP) als Tracer untersucht. Die subcommissuralen Capillaren besitzen ein ungefenstertes, vesikelarmes Endothel, das einer einfachen, durchgehenden Basallamina aufsitzt. In der Umgebung der Capillaren finden sich neben periodisch strukturierten Körpern (PSK) vereinzelt Basallamina-Labyrinthe und regellos angeordnete kollagene Mikrofibrillen. Mit der Perjodsäure-Silbermethenamin-Reaktion lassen sich Glykoproteide im Bereich der Basallamina und der nach außen anschließenden Intercellularspalten darstellen, vereinzelt auch — teils im Bereich der Basallamina, teils ihr eng angeschlossen — Gruppen parallel angeordneter, linearer Strukturen mit einem periodischen Streifenmuster. Saure Mucopolysaccharide sind nur in der lumenseitigen Glykokalyx des Capillarendothels nachweisbar. Der Aufbau der PSK aus Kollagenfilamenten erscheint sehr wahrscheinlich. Vermutungen zur Entstehung dieser hochgeordneten Strukturen werden vorgebracht. Die Traceruntersuchungen ergeben, daß unter normalen Bedingungen in den subcommissuralen Capillaren eine Blut-Hirn-Schranke (BHS) für MRP besteht, die im Endothel lokalisiert ist. Bei einem Teil der Sprague-Dawley-Ratten ist die Barriere geschädigt und der Tracer gelangt über cytopemptische Vesikel in Basallamina und Gefäßumgebung. Der Basallamina und den PSK kommt in solchen Fällen keine besondere Schranken- oder Verteilerfunktion zu. Offenbar bewirkt bei manchen Sprague-Dawley-Ratten die MRP-Injektion über die Freisetzung von endogenen biogenen Aminen aus Mastzellen eine Schädigung der BHS, was bei Wistar-Ratten nicht eintritt.
    Notes: Summary The capillaries of the subcommissural organ (SCO) and their adjacent structures of 38 adult Sprague-Dawley rats and 6 adult Wistar rats were examined in the electron microscope after perfusion fixation. Acid mucopolysaccharides were shown by Alcian Blue and Ruthenium Red, glycoproteins were identified by the periodic acid-silver methenamine technique. Horseradish peroxidase (MRP) was used as a tracer for vascular permeability. The subcommissural organ's capillaries are characterized by an unfenestrated, continuous endothelium, showing only few vesicles; the endothelium is surrounded by a single, continuous basal lamina. Adjacent to the capillaries wall there are “periodically structured bodies” (PSK), labyrinths of the basal lamina and irregularly arranged collagen fibrils. Glycoproteins are found in the basal lamina and within the intercellular clefts; in a few cases groups of parallel arranged, periodically banded linear structures are seen within or adjacent to the basal lamina. Acid mucopolysaccharides are found within the endocapillary layer of capillaries. It seems very likely that PSK represent an atypical arrangement of collagen fibrils. The formation of these structures is discussed. Under normal conditions, MRP, after intravenous injection, does not enter the perivascular space surrounding the capillaries of the SCO. A blood-brain barrier exists at the level of the capillary endothelium. In a few Sprague-Dawley rats MRP seems to alter the permeability of the capillaries. Reaction product of MRP is found within endothelial vesicles and the adjacent structures. It appears that the basal lamina and the PSK are not involved in the barrier mechanism or regulation of transport. In Sprague-Dawley rats intravenous injection of MRP seems to alter the blood-brain barrier by release of endogenous biogenic amines associated with mast cell degranulation. This effect is not observed in Wistar rats.
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  • 11
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    Electronic Resource
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    Anatomy and embryology 144 (1974), S. 173-186 
    ISSN: 1432-0568
    Keywords: Hippocampus ; Neurogenesis ; Autoradiography ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summay The prenatal ontogeny of the hippocampus, including the anterior continuation and induseum griseum, was examined in the rat by means of tritiated thymidine autoradiography. The neurons of the anterior continuation formed between the 16th and 18th days of embryonic development. The neurons of the induseum griseum were formed on the 16th and 17th days of gestation. The pyramidal cells of ammon's horn were formed during the 16th, 17th, 18th, and 19th days of embryogenesis but were preceded by the large interneurons of the stratum lacunosum-moleculare which formed on days 15 and 16 of embryonic life. The granule cells of the superficial layers of the stratum granulosum formed during the 20th, 21st, and 22nd days of gestation.
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  • 12
    ISSN: 1432-0568
    Keywords: Lung ; Stretch receptors ; Light microscopy ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Lappenbronchien (3./6.) (Durchmesser bei mittlerer Inspirationslage 500–700 μ) von männlichen und weiblichen Wistarratten wurden licht- und elektronenmikroskopisch untersucht. Diese Bronchien entsprechen im Wandbau den mittleren Bronchioli größerer Säugetiere. Freie, verzweigte lanzettförmige Terminalfasern werden im Bindegewebe der lamina propria beschrieben. Sie sind in das elastisch muskuläre System der Bronchuswand eingebaut. Die zugehörige markhaltige afferente Nervenfaser ist verzweigt und hat einen Durchmesser von 4–6 μ. Außerdem werden efferente motorische Endigungen an der glatten Bronchialmuskulatur beschrieben. Die freien lanzettförmigen und verzweigten Terminalfasern sind möglicherweise Dehnungsrezeptoren für den Hering Breuer Reflex.
    Notes: Summary In rats the 3rd to 6th bronchi, measuring 500–700 μ in diameter during inspiration, were investigated by light and electron microscopy. The histological appearance of these bronchi is comparable to that of medium sized bronchioles of larger animals. The branched and lanceolate terminals are associated with the connective tissue of the lamina propria and the smooth muscle cell layer. In this way the terminals are bound to the myoelastic system of the bronchial wall. The myelinated afferent fiber is branched and the diameter measures about 4–6 microns. Besides afferent nerve terminals these are numerous efferent endings on the smooth muscle basement laminae. It is supposed that the described receptor represents the pulmonary stretch receptor of the Hering Breuer reflex.
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  • 13
    Electronic Resource
    Electronic Resource
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    Anatomy and embryology 143 (1974), S. 185-203 
    ISSN: 1432-0568
    Keywords: Basement membrane labyrinths ; Cerebral ventricles ; Development ; Rat ; Light and Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Gehirne embryonaler und neugeborener Ratten wurden im Hinblick auf die frühe Entstehung der Basalmembranlabyrinthe licht- und elektronenmikroskopisch untersucht. 1. An den Hirngefäßen embryonaler Ratten der 2. und 3. Fetalwoche kommen zwar bereits Basalmembranen vor, sub- oder interependymale Basalmembranlabyrinthe fehlen aber noch. 2. Basalmembranlabyrinthe werden mit der Perjodsäure-Bisulfit-Aldehydthionin-Methode lichtmikroskopisch ab dem 20. Tag an umschriebenen Stellen des Ventrikelsystems gefunden; elektronenmikroskopisch treten die ersten Basalmembranlabyrinthe am 12. postnatalen Tag auf. 3. Die ersten interependymalen Labyrinthe erscheinen in Erweiterung der interependymalen Spalten in der Nähe von ausgedehnten Golgifeldern. Der Labyrinthinhalt besteht aus einer feinflockigen Substanz. Diese liegt wolkenartig angehäuft gegenüber bogenförmigen Ausbuchtungen lokal verbreiterter Zellmembranen. In Ausbildung begriffene Labyrinthe zeigen eine lamelläre Gliederung. 4. Ab dem 12. postnatalen Tag treten auch an den Basalmembranen der pericapillären Zellen, in denen lichtmikroskopisch Glykoproteide nachweisbar sind, zapfenartige Duplikaturen auf. Die Zapfen sind überwiegend ependymwärts gerichtet. Verbindungen zwischen den Basalmembranzapfen und den interependymalen Basalmembranlabyrinthen werden in den ersten 30 Lebenstagen nicht gefunden. 5. Sowohl an den die interependymalen Labyrinthe begrenzenden Plasmalemmata als auch am Plasmalemm der pericapillären Zellen fallen Stachelsaumbläschen auf, deren Membran in die Zellwand eingebaut wird. Ihr Inhalt scheint in die entstehenden Labyrinthe entleert zu werden. 6. Da sich an den tubulären Enden der Doppellamellen der Dictyosomen Strukturen befinden, die den Stachelsaumbläschen morphologisch gleichen, und da im Bereich des Golgifeldes und im Cytoplasma zwischen diesem und der Zellwand zahlreiche Stachelsaumbläschen liegen, wird angenommen, daß das Material der Basalmembranlabyrinthe dem Golgiapparat entstammt und vermittels der Stachelsaumbläschen zur Zellwand transportiert wird. Bogenförmige Ausbuchtungen lokal verbreiterter Zellmembranen im Bereich entstehender Labyrinthe werden als Reste von Stachelsaumbläschen aufgefaßt, deren Membran in die Zellwand eingebaut wurde. 7. Da die phylogenetische Zunahme des Hirnmantels mit einem Verlust der langen in das Gehirn reichenden basalen Ependymfortsätze an den größten Teilen der Ventrikelwand einhergeht und niedere Tiere noch nicht über Basalmenbranlabyrinthe verfügen, wird angenommen, daß diese die Transportfunktion für Stoffe aus dem Liquor übernommen haben, die vordem nach allgemeiner Auffassung über die langen Fortsätze in das Gehirn gelangten.
    Notes: Summary The brains of embryonic and new-born rats were investigated by means of light- and electron microscopy with regard to the early formation of basement membrane labyrinths. 1. Though basement membranes are already found around the brain capillaries of embryonic rats from the 2nd week of pregnancy, sub- and interependymal basement membrane labyrinths are still absent. 2. Basement membrane labyrinths, being demonstrable for light microscopy by a periodicacid-bisulfite-aldehydethionin-method, appear around the 20th day after birth at certain places of the ventricular system. By means of electron microscopy, basement membrane labyrinths have first been detected at the 12th postnatal day. 3. The earliest interependymal basement membrane labyrinths are found in enlargements of the interependymal spaces near a distended Golgi apparatus. The contents of the labyrinths, being composed of a loose flocculent material, are of a lamellar structure. In the intercellular space the material is situated opposite bow-shaped excavations of local broadenings of cell membranes. 4. From the 12th postnatal day, plug-like duplications of basement membranes occur at the ependymal side of the pericapillar cells, which contain glycoproteids. The plugs of basement membranes are directed towards the ependymal layer. No connections between the interependymal basement membrane labyrinths and the plugs of pericapillary basement membranes exist within the first 30 days of life. 5. At the plasmalemma of ependymal cells bordering the interependymal labyrinths, and at the cell membrane of pericapillary cells, coated vesicles are to be found, which are fused with the cell membrane. The contents of these vesicles seem to be released into the developing labyrinths. 6. At the tubular ends of dictyosomes, coated vesicle-like structures can be demonstrated. In the environment of the Golgi apparatus many coated vesicles are situated; they can even be found between the Golgi apparatus and the walls of labyrinthś. Therefore the coated vesicles are considered to be transport vesicles, transporting the material which is formed in the Golgi apparatus towards the cell membrane. 7. Since the phylogenetic increase of the brain mantle is accompanied by loss of the long processes of ependymal cells that reach far into the brain, and since lower animals have no basement membrane labyrinths, it is suggested that the basement membrane labyrinths have a transport functions for material from the cerebrospinal fluid which in lower animals is assumed to be transported by the long processes of ependymal cells.
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  • 14
    ISSN: 1432-0568
    Keywords: Colonic mucosa ; Mouse ; Vacuolated cells ; Electron microscopy ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Swiss ICR adult male mice were used to analyse regional morphologic differences in the mucosa of the colon. The three cell types recently described in the descending colon of the mouse were also observed in the transverse and in the ascending colon. However the vacuolated cells of the crypts have presented different morphological characteristics depending on their localisation. In the ascending colon, they exhibited small supranuclear vesicles in contrast to the large vesicles observed in the descending colon. Several cell combining features of argentaffin-vacuolated, goblet-vacuolated and goblet-argentaffin cells have been observed. Furthermore a special type of granule referred to as a secondary lysosome was observed in the peripheral area of the typical goblet cells.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 144 (1974), S. 195-203 
    ISSN: 1432-0568
    Keywords: Development ; Adrenal glands ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Untersuchung der vorgeburtlichen Entwicklung der Nebennieren erfolgte an H.-E.-Schnitten und wurde ergänzt durch den Nachweis alkalischer Phosphatase. 1. Markzellen beginnen mit 11–12 Tagen in das Rindenblastem einzuwandern. Mit 14 Tagen a.p. ist die Einwanderung bereits abgeschlossen, d.h. viel früher als bei menschlichen Embryonen entsprechenden Alters. 2. Der Cortex beginnt sich am 11. Tag zu entwickeln, wie bei menschlichen Embryonen vergleichbaren Alters. Vor der Geburt kann bei der Maus nicht zwischen einem “fetalen” und “permanenten” Cortex unterschieden werden. 3. Eine frühzeitige Einwanderung von versprengten Geschlechtszellen kann in der Cortexanlage durch die Reaktion auf alkalische Phosphatase nachgewiesen werden. Später verschwinden sie wieder. Eine Infiltration von Leuko-und Lymphocyten besteht nicht. Beim Herannahen des Geburtszeitpunktes treten aber Blutbildungsherde auf.
    Notes: Summary A detailed reinvestigation of the prenatal development of the adrenal gland has been carried out, using H.-E. sections supplemented by investigation of alcaline phosphatase activity. 1. Medullary cells start to invade the cortex blastema at 11–12 days. Immigration is completed at 14 days a.p., i.e. much earlier than in human embryos of corresponding age. 2. Cortex development starts at 11 days, like in human embryos of corresponding age. Before birth, there is no distinction between “fetal” and “permanent” cortex in mice. 3. Early invasion of gonocytes into the cortex blastema can be demonstrated by alcaline phosphatase reaction. Later on they disappear. There is no infiltration of leuco-and lymphocytes. Near term foci of blood-forming cells are appearing.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 144 (1974), S. 205-214 
    ISSN: 1432-0568
    Keywords: Adrenal gland ; Juxtamedullary X-zone ; Mouse ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die postnatale Entwicklung der Nebennieren wurde an hybriden Mäusen (Kreuzung der Inzuchtstämme C57BL/6 und CBA) und an nu/+ Mäusen (BALB/c) untersucht. Dabei standen uns von weiblichen und männlichen Tieren beider Stämme Schnittserien der folgenden Stadien zur Verfügung: 1, 7, 14, 21, 42, 63 und 84 Tage. Neben Zona glomerulosa und Zona fasciculata weist die Nebennierenrinde 2–3 Wochen alter Mäuse zwei innere Schichten auf. An die dem Mark anliegende, schon mehrfach beschriebene X-Zone schließt sich nach außen ein Gürtel kleiner Zellen an. Diese zwischen X-Zone und Fasciculata gelegene, bei Weibschen stärker ausgeprägte Rindenschicht bildet sich mit dem Verschwinden der X-Zone zurück. Wegen ihrer morphodynamischen und wahrscheinlich auch funktionellen Eigenständigkeit haben wir diese Schicht von der X-Zone abgetrennt und als kleinzellige Zone bezeichnet. Auf Grund unserer Beobachtungen neigen wir zur Ansicht, daß die definitive Zona reticularis aus der kleinzelligen Zone hervorgeht. Der Zeitpunkt beginnender Rückbildung der X-Zone zegt neben den bekannten geschlechtsabhängigen Unterschieden eine ganz erhebliche Variabilität (bis 10 Wochen) zwischen den verschiedenen Tierstämmen. Die X-Zone der Maus und die fetale Zone der menschlichen Nebenniere können—obwohl beides vorübergehende Strukturen—, wegen ihrer verschiedenartigen Entwicklung kaum als Analoga betrachtet werden.
    Notes: Summary The postnatal development of the adrenal glands was investigated in hybrid mice (from crossing the two inbred strains C57BL/6 and CBA) and in nu/+ mice (BALB/c). Serial sections of the following stages: day 1, 7, 14, 21, 42, 63, and 84 respectively from both strains and sexes were studied. The adrenal cortex of 2–3 week old mice is structurally differentiated into the zona glomerulosa, the zona fasciculata and two inner zones: 1: the well known x-zone surrounding the medulla; 2: a distinct zone (more pronounced in females, than in males) of small cells lying between the x-zone and the zona fasciculata. The latter disappears parallel to the removal of the x-zone. In view of the distinct morphological, developmental and probably even functional individuality of this zone, it was separated from the x-zone and given the name “zone of small cells”. It is assumed, that the definitive zona reticularis originates from the zone of small cells. The time at which the x-zone starts to degenerate depends on the sex, and varies considerably from one strain to another. The x-zone of the mouse and the fetal zone of the human adrenal gland—both transitory structures—differ too much in their development to be considered as analogous structures. New-born mice show a positive chromaffine reaction of the medullary cells. During the first 3 weeks the intensity of reaction increases considerably and then remains at the higher level for the time of further development.
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  • 17
    ISSN: 1432-0568
    Keywords: Motor nerve terminals ; Methylene blue stain ; Hindlimb muscles ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary With methylene blue stain, three morphological types of motor nerve terminals were distinguished in hindlimb muscles (extensor digitorum longus, semitendinosus, soleus, and tibialis anterior muscles) of rat. Type A terminals possess many long thin branches with numerous minute swellings, type C ones possess few and thick terminal branches with few large swellings, and type B ones possess intermediate characteristics. The frequencies of occurrence of these types are characteristic for each muscle and differ between different hindlimb muscles. Specifically, soleus muscle contains a much higher proportion of type B terminals than other hindlimb muscles, and the superficial part of tibialis anterior muscle contains a higher proportion of type A terminals and a lower proportion of type C ones than the deep part. The frequencies of occurrence of types A, B, and C terminals closely parallel the frequencies of “white”, “intermediate”, and “red” muscle fibers (as determined by a fat stain), respectively, in the different muscles. As also suggested previously for the diaphragm, it is concluded that three morphological types of motor nerve terminals each may innervate one of three types of muscle fibers.
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  • 18
    ISSN: 1432-0568
    Keywords: Development ; Genetics ; Mouse ; Vertebrae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The recessive mutation, rachiterata, reduces the number of cervical vertebrae to 6 by shifting the cervico-thoracic boundary in a cranial direction, and produces partial duplication of the neural arch of the axis. Rachiterata also produces malformations of thoraco-lumbar vertebrae, often associated with fusions of ribs. These malformations are caused by a disturbed arrangement of somites first detectable in 11-day embryos.
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  • 19
    ISSN: 1432-0568
    Keywords: Embryology ; Mouse ; Muscle differentiation ; Physiologic cell necroses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mice embryos from day 9 to 15 p.c. have been studied by 1. Supravital staining of the whole embryo with nile blue sulfate. 2. Light and 3. Electron microscopic investigation of serial sections from the longitudinal axis of the back of the trunk. Nile blue sulfate staining revealed segmental necroses in the back of mice embryos centrally between the intersegmental arteries. Necroses appeared in the cranial myotomes and extended to the caudal ones during the days 9 to 13 p.c. By light microscopy the necroses extended in the centre of the myotome to the ventromedial margin. Electron microscopy revealed in this area myoblast-like cells rich in filaments, arranged in parallel without striation. A part of these myoblasts were electron-opaque and the nucleus was no longer evident. Forming vortices of filaments, these cells on the cranial and caudal end of the myotomes ceased fusion with the more centrally situated myoblasts. Vortices of filaments were also found in phagolysosomes of macrophages on day 12 p.c. On the same day of gestation we found an unsegmented myoblastema with irregular long myoblasts and striated polynuclear muscle fibres, arranged parallel to the neural tube. Between and parallel to the muscle fibres elongated individual cells could be seen, growing necrotic. Their nuclei were electron-dense with the chromatin clumping cap-like on the inner nuclear membrane. Fragments of myofibrils, corresponding approximately to sarcomeres, were dispersed irregularly as filament logs in the cytoplasm. Logs of filaments were bent at an obtuse angle, partly showing remnants of Z line material. In this stage of necrosis cells were phagocytized by macrophages. After disintegration of the segmental arrangement in scleroblastemata and myoblastemata a segmental rearrangement was not achieved by segmental shifting or by necrotic liquefaction zones. Whether the described cell necroses are due to differentiation, or even to phylogenetic causes is discussed.
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  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 145 (1974), S. 169-186 
    ISSN: 1432-0568
    Keywords: Renal innervation ; Rat ; Peripheral nerves ; Neuroeffector zones ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der Rattenniere werden die muskelzellhaltigen arteriellen Gefäße und der juxtaglomeruläre Apparat innerviert. Blutgefäße mit Pericyten, porenhaltige Capillaren sowie die Tubuli der Rinde und des Markes werden nicht von Nervenfasern begleitet. Ganglienzellen wurden in der Rattenniere nicht beobachtet. Periphere Nerven mit einem ein-bis zweischichtigen Perineurium kommen im paravasalen Gewebe der Interlobar- und Arcuata-Arterien vor; sie enthalten neben zahlreichen marklosen Nervenfasern gewöhnlich auch 2–4 markhaltige. Nervenfaser-Bündel ohne perineurale Scheide finden sich im paravasalen Gewebe der Arcuata- und Interlobular-Arterien. Darüber hinaus sind in unmittelbarer Nachbarschaft der großen Arterien (Interlobar-, Arcuata- und Inter-lobular-arterien) und der Vasa afferentia marklose Nervenfasern und freie Axone vorhanden, die auch die proximalen Abschnitte der Vasa efferentia der subcapsulären und intermediären Rindenschicht begleiten. Im Nierenmark werden die juxtamedullären Vasa efferentia und die Arteriolae rectae innerviert; marklose Nervenfasern und freie Axone sind nur bis zur Außen-Innenstreifen-Grenze nachweisbar. Die Innervation der muskelzellhaltigen arteriellen Gefäße erfolgt durch aufgetriebene Axonabschnitte (Neuroeffektor-Zonen), die vorwiegend agranuläre Vesikel enthalten. Diese Strukturen liegen stets an der Grenze von Adventitia und Media bzw. Elastica externa; zwischen den glatten Muskelzellender Media wurden keine vesikelhaltigen Axonabschnitte gefunden. Als minimaler Abstand zwischen den vesikelhaltigen Axonabschnitten und den von einer Basalmembran umschlossenen glatten Muskelzellen (neuromuskuläre Distanz) wurden 600 Å gemessen. Die vorliegenden Ergebnisse werden mit den fluoreszenzmikroskopischen und histochemischen Untersuchungen über die adrenerge und cholinerge Innervation der Niere verglichen. Die sich aus diesem Vergleich ergebenden Probleme und funktionellen Konsequenzen für die Innervation der Niere sowie die Natur der cholinergen Fasern (afferente oder postganglionäre parasympathische Fasern) werden diskutiert.
    Notes: Summary The innervation of the rat kidney is defined by a system which supplies those arterial blood vessels whose walls contain smooth muscle cells and the juxtaglomerular apparatus. Vessels containing pericytes, or those vessels composed of an endothelium only, as well as the tubules of both the cortex and medulla, are not innervated. Furthermore, ganglion cells do not occur in the rat kidney. The nervous apparatus of the rat kidney consists of peripheral vegetative nerves, ensheathed by a perineurium, with 2–4 myelinated fibers running in the paravasal tissue of the interlobar and arcuate arteries, and of nerve bundles without a perineurial sheath in the paravasal tissue of the arcuate and interlobular arteries. Non-myelinated fibers and free axons occur in the immediate vicinity of the great arteries (interlobar, arcuate, and interlobular) and the vasa afferentia. Nerve fibers and free axons are also seen in the vicinity of only the proximal parts of those vasa efferentia which supply the cortical capillary plexus. The arteriolae rectae of the medulla, and their vasa efferentia, from which they arise, are innervated by non-myelinated fibers and free axons which accompany these arterial vessels only to the boundary of the outer and inner stripe of the outer zone of the medulla. The functional innervation of those vessels with smooth muscle cells results from neuro-effector zones which predominantly show agranular vesicles. These structures were never seen between the smooth muscle cells within the media; the minimum neuromuscular distance was 600 Å. The present findings are correlated with the lightmicroscopically demonstrated adrenergic and cholinergic innervation. The resultant problems and functional consequences of the innervation of the kidney, especially the nature of the cholinergic fibers (afferent or post-ganglionic parasympathetic fibers) are briefly discussed.
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  • 21
    ISSN: 1432-0568
    Keywords: Rat ; Liver ; Bile ducts ; Cilia ; Scanning Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Numerous cilia have been demonstrated by SEM in cells of rat perilobular and portal bile ducts and ductules. Generally these cilia appear as long, cylindrical evaginations of the plasma membrane. Some of them are so long that, curving and twisting at many points, they cross the ductal lumen. It has been suggested that they may be related to a continual mixing up and propulsion of the bile product down the biliary tree.
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  • 22
    ISSN: 1432-0568
    Keywords: Dorsal lateral geniculate nucleus ; Morphology (ultrastructure) ; Mouse ; Synaptic vesicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neuronal perikarya, dendrites, extraglomerular neuropil, and synaptic glomeruli were examined by electron microscopy in the dorsal lateral geniculate nucleus (LGd) of the mouse. Particular attention was paid to boutons containing “flattened” synaptic vesicles. In line with recent studies of rat LGd (Lieberman and Webster, 1972; Lieberman, 1973), but in contrast to the findings of Rafols and Valverde (1973) on the mouse LGd, two distinct classes of ‘flat’-vesicle-containing boutons could be distinguished. P-boutons—were traced to and probably originate entirely from the presynaptic dendrites of the intrinsic neurons. They are concentrated within the glomeruli and are postsynaptic as well as presynaptic, being the intermediate elements in numerous intraglomerular serial synapses. F-boutons—are interpreted as axon terminals and are exclusively presynaptic. Some were traced from myelinated fibres. Synaptic vesicles are more concentrated in F-boutons than in P-boutons, appear flatter, and lie in a darker matrix. F-boutons synapse extensively in the extraglomerular neuropil, but are outnumbered by P-boutons in the glomeruli. The synaptic relationships established within the glomeruli are summarized.
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  • 23
    ISSN: 1432-0568
    Keywords: Pantothenic acid deficiency ; Corticotropin-releasing factor ; Corticoids ; Histologie ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the outer layer of the rat median eminence “Gomori-positive” granules occur which are assumed to be the morphological correlate of the corticotropin-releasing factor (CRF). The present study was carried out in order to establish whether the amount of these CRF-granules is influenced by a pantothenic acid (PA)-deficiency, which is known to result in an inhibition of corticosteroid production. Female SPF Wistar rats were used. PA-deficiency was induced by PA-free nutrition and/or administration of the PA-antagonist Ω-methyl-PA. Corresponding experimental groups were given either tap water or a solution of 1% NaCl and 5% glucose in tap water to drink. In rats fed with a diet free of PA and in addition treated with Ω-methyl-PA a severe disturbance of the corticoid balance developed within 6 weeks. The corticosterone production was depressed to about 11–16% of the control values. The adrenal cortex showed necrotic changes which either involved the whole parenchyma or were confined to the inner zones. In those animals in which a subcapsular region, in its extent corresponding to the zona glomerulosa, remained intact, an augmentation of the CRF-granules was observed. In those animals, however, in which the whole adrenal cortex was damaged, the amount of CRF-granules did not increase. Administration of the 1% NaCl containing drinking fluid did not influence the augmentation of the CRF granules, but had a protective effect on the development of necrotic changes in the zona glomerulosa of the adrenal cortex. The findings show that a functional relationship exists between the inner zones of the adrenal cortex and the CRF-granules in the median eminence.
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  • 24
    ISSN: 1432-0568
    Keywords: Neurohypophysis ; Neuro-vascular contacts ; Neuro-glial synaptoid contacts ; Dehydration ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The posterior lobe of the hypophysis consists of neurosecretory nerve fibres and glial cells, both abutting on the perivascular space of sinusoidal capillaries. Nerve fiberes and glial cells are connected with each other by a high number of synaptoid contacts. Several ultrastructural changes following dehydration have been described by other authors. This study presents the data of some morphometric investigations on normal and dehydrated rats. The relative extent of neuro-vascular contacts is not contstant; it increases significantly from 52 (±2.8)% in normal rats to 67(±1.2)% in rats with a dehydration time of 3 days. Correspondingly the extent of glio-vascular contacts is diminished. In addition, water-deprived animals show a clear increase in the number of neuro-glial synaptoid contacts with 3.1 (±0.4) per square unit nervous tissue compared to 2.1 (±0.3) per Square unit in untreated controls. These results indicate a dynamic motility of neuronal and glial elements depending on functional conditions, as was found for the external layer of the median eminence. Furthermore there seems to be a relationship between secretory activity and the number of neuroglial synaptoid contacts.
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  • 25
    ISSN: 1432-0568
    Keywords: Leydig cells ; Differentiation ; Explants ; Ultrastructure ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Testes of newborn mice not older than one day were transplanted into the anterior chamber of one eye of an adult male white Holtzman rat. The events observed in the Leydig cells of the grafted testes can be divided into two periods. Period one is marked by differentiation; period two, by dedifferentiation. In period one, the lipid and glycogen inclusions disappear, possibly owing to the gonadotropins of the host. In period two, which starts after day 15 post-grafting, the lipids and glycogen reappear; the Leydig cells now contain residual bodies, whereas the S.E.R. disappears. Immunological mechanisms can be implicated; it is suggested that the Leydig cells dedifferentiate because the host's gonadotropins may be incapable of evoking and/or activating the genetic memory of the grafted Leydig cells.
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  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 27 (1974), S. 25-32 
    ISSN: 1432-0533
    Keywords: Experimental CNS Tumours ; Nitrosomethylurea ; Ethylnitrosourea ; Primary Cultures ; Tumour Classification ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary By means of the explant technique a series of primary tumours induced by methylnitrosourea (MNU) or ethylnitrosourea (ENU) in the brain of rats were cultured in vitro. The morphology of isomorphic oligodendrogliomas, astrocytomas, glioblastomas and sarcomas under in vitro conditions is described. All these neoplasias show a very distinct morphological picture and growth behaviour, thus permitting their classification. Most of the tumours tend to anaplastic changes during longer cultivation, but in some cases, preferably in well differentiated gliomas, the cytological properties are maintained even during longterm cultivation. The role of anaplasia and intermingling of different neoplastic cell types in experimental tumours are discussed.
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  • 27
    ISSN: 1432-0533
    Keywords: Allergic Encephalomyelitis ; Organ Culture ; Brain ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Experimental allergic encephalomyelitis (EAE) developed in 15 of 30 rats injected with a mixture of Freund's adjuvant and homogenized guinea pig brain, and killed after 6–29 days. The incidence and severity of the disease increased with time after inoculation and in 2 animals involvement of the epiphysis, not previously reported in EAE, was detected. Toxic effects on cells in cultured adult rat cerebellar cortical tissue were produced by exposure for 24 h to the sera of rats killed 12–29 days after inoculation either with the antigenic suspension or with adjuvant alone. Severe toxicity to axons (widespread fragmentation) was produced only by the sera of animals injected with antigenic inocula and killed 17–29 days later. Severe axonal toxicity was not, however, correlated with the presence of EAE in the rats from which the sera were taken. It was not possible to assess myelinotoxic effects in the system used. It is suggested that the organ culture technique may detect the presence in the sera of inoculated animals of toxic principles which, owing to the blood-brain barrier, do not normally contribute to the pathogenesis of EAE.
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  • 28
    ISSN: 1432-0533
    Keywords: Cholesterol Inhibitors ; Cerebrum ; Neuronal Inclusions ; Oligodendroglial Degeneration ; Rat ; Abnormal Sterols
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Wistar strain of rats received daily intraperitoneal or oral administration of Triparanol, 250 mg per kg of body weight or 20,25-diazacholesterol either 30 mg or 60 mg per kg of body weight starting at the age of 5 days old. Prominent intracytoplasmic osmiophilic inclusions identical to those found in the rats treated with AY9944 (Suzukiet al., 1973) and degeneration of myelin sheaths and oligodendroglia were seen in the myelinating white matter of rats sacrificed after 3, 6, and 9 injections of Triparanol. In diazacholesterol-treated animals, a few identical inclusions were seen in the cortical neurons but only slight changes were seen in oligodendroglia. Biochemical analysis of the brains of the rats receiving Triparanol revealed a large accumulation ofΔ 7,24-cholestadiene-3β-ol and lesser amounts of desmosterol. The brains of the animals treated with diazacholesterol revealed massive accumulation of desmosterol and a minor sterol component, probablyΔ 5,7,24-cholestatriene-3β-ol. Since AY9944, which results in a massive accumulation of 7 dehydrocholesterol (Δ 5,7-cholestadiene-3β-ol) and two other sterols,Δ 7,24-cholestadiene-3β-ol andΔ 5,7,24-cholestatriene-3β-ol, will produce identical neuropathological lesions to those seen in Triparanol treated animals, and since the lesion produced in diazacholesterol treated animals was very slight, there appears to be a correlation between the presence of sterols with a double bond at the 7-position and neuropathological lesions in young rats.
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  • 29
    ISSN: 1432-0533
    Keywords: Chronic Lead Intoxication ; Rat ; Ultrastructure ; Microglia ; Pericytes ; Monocytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Wistar rats of both sexes and the same litter were exposed to chronic lead intoxication from birth untill sacrifice 9 months later. Lead was administered as 0.4% solution of lead nitrate in drinking water. Samples from the parietal brain cortex were examined electron microscopically following intracardiac perfusion with paraformaldehyde-glutaraldehyde solution. Similar changes were observed in the microglial cells and the vascular pericytes whereas all the other tissue elements appeared intact. Both cell types hypertrophied, the microglia assumed characteristic spindle or rod shape, the cell organelles increased, the microglial endoplasmic reticulum widened strongly and a large number of lipid inclusions appeared. The latter consisted of large lipid droplets of varying size and shape, containing multiple zones of low density, and a dense component with a coarse granular structure. The similarity in the response of both cell entities to the lesion as well as some probable functions of microglial cells and their relationship to vascular pericytes are discussed.
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  • 30
    ISSN: 1432-0827
    Keywords: Sodium fluoride ; Osteoporosis ; Bone ; Strength ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'utilisation thérapeutique de fluorure de sodium a été recommandée dans le traitement de diverses maladies osseuses ostéopéniques. Cet emploi est basé principalement sur les effects ostéosclérotiques bien connus du fluorure de sodium, mais on connait mal son effet sur la force de résistance osseuse. L'influence de diverses concentrations de fluorure de sodium sur la force de résistance osseuse de jeunes rats soumis à des régimes riches et pauvres en calcium a été étudiée. L'administration de fluorure de sodium augmente le diamètre osseux, indiquant une stimulation de la formation de l'os périosté, mais la force de résistance osseuse est réduite ou non modifiée par l'ingestion de fluor.
    Abstract: Zusammenfassung Die therapeutische Verwendung von Natriumfluorid ist für eine Anzahl von Knochenmangel-Krankheiten empfohlen worden. Die Empfehlungen basieren hauptsächlich auf den bekannten osteosklerotischen Wirkungen von Natriumfluorid; über dessen Effekt auf die Knochenstärke ist wenig bekannt. In dieser Arbeit wurde der Einfluß verschiedener Konzentrationen von Natriumfluorid auf die Knochenstärken von wachsenden Ratten mit hoher und niederer Calciumeinnahme untersucht. Die Verabreichung von Natriumfluorid erhöhte den Knochendurchmesser, was auf eine Stimulierung der Periostbildung hinwies, die Knochenstärke wurde jedoch durch Fluorideinnahme herabgesetzt oder nicht beeinflußt.
    Notes: Abstract The therapeutic use of sodium fluoride has been recommended in a variety of osteopenic bone diseases. The recommendations are based mainly on the known osteosclerotic effects of sodium fluoride and little information is available as to its effect on bone strength. The influence of various concentrations of sodium fluoride on bone strength in growing rats on high and low calcium diets was studied. The administration of sodium fluoride increased bone diameter, indicating stimulation of periosteal bone formation, but bone strength was reduced or not affected by fluoride ingestion.
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  • 31
    ISSN: 1433-8580
    Keywords: Coprophagy ; Rat ; Calcium metabolism ; Bone morphology ; Immobilization ; Koprophagie ; Ratte ; Calciumstoffwechsel ; Knochenmorphologie ; Immobilisierung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Wir untersuchten den Einfluß der Koprophagie auf den Calciumstoffwechsel der Ratte. 20 Versuchstiere wurden durch Einschnüren in einen Lederpanzer an der Koprophagie gehindert und mit 21 Kontrolltieren gleicher Futteraufnahme verglichen. Die Kinetik des Calciumstoffwechsels wurde unter Verwendung von45Ca als Tracer analysiert. Die radiochemischen Resultate wurden mit den histologischen Beobachtungen an den Epi-Metaphysen der Kniegelenke verglichen. Bei den Versuchstieren mit verhinderter Koprophagie fanden wir: 1. ein hochsignifikant niedrigeres Körpergewicht; 2. eine hochsignifikante Verkleinerung folgender Parameter des Calciumstoffwechsels: Compartmentgröße und Austauschrate zwischen ihnen, Calciumausscheidungsraten, Knochenan- und -abbau; 3. eine Verschmälerung der Wachstumsfuge, verkürzte und verschmälerte primäre Knochenbälkchen, verminderte sekundäre metaphysäre Spongiosa. Bei 4 Versuchstieren, die in Lederpanzern gehalten, denen jedoch die Koprophagie ermöglicht war, wurden gleichartige histologische Veränderungen wie bei verhinderter Koprophagie festgestellt. Es wird gefolgert, daß die Verhinderung der Koprophagie keinen meßbaren Einfluß auf die Parameter des Calciumstoffwechsels hat.
    Notes: Summary We investigated the influence of coprophagy on the calcium metabolism of the rat. 20 experimental animals were prevented from coprophagy by wrapping them in leather harnesses and compared with 21 controls on the same food intake. Kinetics of calcium metabolism were analysed using45Ca as tracer. The radiochemical results were compared with the histological observations in the epi-metaphyses of the knee joints. In the experimental animals prevented from coprophagy we found: 1. a highly significant lower body weight; 2. a highly significant diminution of the following parameters of calcium metabolism: compartment sizes and exchange rate between them, calcium excretion rates, bone accretion and resorption; 3. a narrower epiphyseal growth cartilage, clearly shorter and narrower primary trabeculae, rarefied secondary metaphyseal trabeculae. Histological alterations identical to those observed with coprophagy prevented, were found in 4 animals kept in harnesses but with coprophagy allowed. It is concluded that prevention of coprophagy has no measurable influence on the parameters of calcium metabolism.
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  • 32
    ISSN: 1433-8580
    Keywords: D-penicillamine ; Acetazolamide ; Renal excretion ; Rat ; D-Penicillamin ; Acetazolamid ; Renale Exkretion ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die renale Ausscheidung von D-Penicillamin läßt sich weder durch Probenecid noch durch N-Methylnicotinamid oder NH4Cl beeinflussen. Acetazolamid bewirkt eine erhöhte Retention von D-Penicillamin in Haut und Muskulatur und hemmt dessen renale Ausscheidung, hat jedoch keinen Effekt auf die Dekorporationswirksamkeit von D-Penicillamin bei60Co. Die möglichen Ursachen des Einflusses von Acetazolamid auf die Verteilung und Exkretion von D-Penicillamin werden diskutiert.
    Notes: Summary The renal excretion of D-penicillamine is not influenced by probenecid, N-methylnicotinamide, and NH4Cl. Acetazolamide brings about an increased retention of D-penicillamine in skin and muscles and lowers its urinary excretion, but does not exhibit any influence on the efficacy of D-penicillamine in removing internally deposited60Co. The possible causes for the action of acetazolamide on the distribution and excretion of D-penicillamine are discussed.
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  • 33
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    Research in experimental medicine 162 (1974), S. 63-66 
    ISSN: 1433-8580
    Keywords: Rhyolithic pumice ; Ferrihexacyanoferrate (II) ; Thallium ; Rat ; Rhyolithischer Bims ; Ferrihexacyanoferrat (II) ; Thallium ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Orale Verabfolgung von rhyolithischem Bims bewirkt eine herabgesetzte Retention von Thallium in den Geweben. Die Wirksamkeit von Rhyolith zeigt eine ausgeprägte Dosisabhängigkeit, ist aber geringer als die von Ferrihexacyanoferrat (II).
    Notes: Summary Oral administration of rhyolith leads to a diminished retention of thallium by the tissues. The effectiveness of rhyolith markedly depends on its dosage, but is surpassed by that of ferrihexacyanoferrate (II).
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  • 34
    ISSN: 1432-2072
    Keywords: Locomotor Activity ; Mouse ; Morphine ; Narcotic Antagonists
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Morphine-induced locomotor activity in mice has been investigated but there appear to be only a small number of reports on the effects of narcotic antagonists on this increased activity. Also, it is well known that some narcotic antagonists can act as both morphine antagonists and analgesics in nociceptive assays, but there have been few demonstrations of this stimulant and antagonistic action with locomotor activity studies. In this study, six compounds (cyclazocine levallorphan, diprenorphine (M-5050), nalorphine, naloxone, and naltrexone) have been investigated in regard to their activity as antagonists of morphine-induced locomotor activity and in regard to their ability to stimulate locomotor activity themselves. All six compounds antagonized the effect of morphine, but only cyclazocine and levallorphan produced any significant stimulation of locomotor activity by themselves at the doses tested. This study indicates that changes in mouse locomotor activity can be used successfully to monitor the interaction between morphine and narcotic antagonists and that locomotor activity studies can also be used to study the stimulant (agonist) properties of narcotic antagonists.
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  • 35
    ISSN: 1432-2072
    Keywords: 6-Hydroxydopa ; Rat ; Behaviour ; Biogenic Amines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The influence of 6-hydroxydopa (6-HDP) injected into the lateral ventricles of rat brain on the behaviour of animals was examined. The level of noradrenaline (NA), 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in discrete areas of the brain was also measured. 6-HDP was injected in a dose of 100 or 150 Μg into both lateral ventricles, or in a dose of 200 Μg into the right lateral ventricle. Immediately after 6-HDP injection, circling movements, convulsions, aggressive behaviour, and Stereotypic activity were seen. These components of behaviour were most obvious during the first hour after injection of 6-HDP. During one month after 6-HDP administration the behaviour of rats did not differ significantly from the behaviour of control animals, only very subtle differences in behaviour being seen. The dose of 150 Μg of 6-HDP caused aphagia and loss of body weigth during the first 5 days after treatment. 6-HDP also caused hypothermia. 20 min after administration of 200 Μg of 6-HDP a decrease of the NA level but no changes in the 5-HT level in the brain cortex were seen. The same changes were observed 1 month after 6-HDP treatment. The dose of 150 Μg of 6-HDP decreased the NA level in the brain cortex, cerebellum, mesencephalon and brain stem 5 days after treatment. 5-HT content was not changed and the 5-HIAA level was increased in the same brain areas. The dose of 100 Μg of 6-HDP, 2 weeks after the treatment decreased the content of NA in the brain cortex, cerebellum, hypothalamus and brain stem without changes in 5-HT content. 5-HIAA level was elevated only in the brain stem. It is concluded that 6-HDP is a long-acting potent depletor of NA in rat brain. There is a different sensitivity of brain areas to the depleting effect of 6-HDP. 6-HDP does not deplete the 5-HT content of discrete areas of brain but increases the level of 5-HIAA. 6-HDP causes distinct behavioural changes shortly after the treatment. It does not change the behaviour of rats between 1 and 30 days after its administration.
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  • 36
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    Pflügers Archiv 352 (1974), S. 121-133 
    ISSN: 1432-2013
    Keywords: Urate ; Protein Interaction ; Uptake by Erythrocytes ; Renal Reabsorption ; Man ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Interaction of urate with human and rat plasma was studied by a dialysis technique at different temperatures. At 4° C a certain fraction of urate is bound to proteins. However, this fraction diminishes with increasing temperature and at 37° C only some 7–8% (in man) and 2% (in rat) interact with proteins. The finding that urate is almost completely filtered in the glomerulus is discussed. In body areas exposed to low temperatures protein binding of urate may be of importance. Urate uptake by erythrocytes is characterized by two components: a fast component equilibrating almost immediately at about 7% in man and 17% in rat and a slow component reaching equilibrium after 60 min, at 28% and 36%, respectively. The process is described by a mathematical formula. Lowering of the temperature mainly diminishes uptake by the slow component withQ 10-values ranging between 1.5 and 4.0. In the observed range of concentrations the uptake process does not saturate. The results at lower pH-values suggest that it is unionized uric acid which is transported by the slow component. Application of the data to kidney medulla supports the hypothesis that erythrocytes and, probably, to a lesser extent plasma proteins serve as vehicles for urate reabsorption in the countercurrent system. Such a temporary interaction enables uric acid to escape recirculation and to leave the kidney medulla.
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  • 37
    ISSN: 1432-2072
    Keywords: LSD-25 ; UML ; 5-HT ; Brain ; Platelets ; Behaviour ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Factorial analysis of rat cerebral 5-HT values observed following intraperitoneal LSD-25 and UML (1-methyl-d-lysergic acid butanolamide) showed that the highly significant decrease induced by both drugs was independent of dose and that the effect of both drugs was the same. Increased platelet 5-HT values were also obtained with each drug. These findings suggest that the psychotomimetic effect of LSD-25 is not due to changes in cerebral 5-HT, since a relationship can probably be postulated between such an effect in man and the effect of LSD-25 on conditioned behaviour in the rat. It is also felt that the fact that these drugs decrease and increase cerebral and platelet values respectively may be of assistance in the interpretation of data relating to platelet 5-HT patterns in man under psychiatric conditions and during treatment with psychotropic drugs.
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  • 38
    ISSN: 1432-2072
    Keywords: Methamphetamine ; Rat ; Conditioned ; Aversion ; Space ; Saccharin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Three experiments were performed on Sprague-Dawley derived rats in which 3.0 mg/kg, i.p., injections of methamphetamine were paired with either, (1) a distinctive spatial enclosure, i.e., either a black or gray portion of a shuttle box with discriminably different flooring, (2) the enclosure plus 0.1% saccharin solution availability in the home cage, or (3) the enclosure plus 0.1% saccharin solution availability in that area. Following three drug pairings which alternated with saline injections paired with a different enclosure or enclosure plus H2O availability, a choice of either spatial (1), or spatial plus gustatory stimuli (2,3) which included the original CS's, were presented under non-drug, non-injection conditions. Control groups received saline injections each day under identical conditions. No aversion to the enclosed area, which had been paired with the drug was demonstrated under (1), gustatory (P=0.005) but not spatial aversion was in evidence in the second paradigm, and spatial (P=0.01) and gustatory (P〈0.01) aversion was exhibited in the last study. It was concluded that subsequent aversion to distinctive spatial enclosures following methamphetamine injections was not as strong an effect as similar aversions to gustatory stimuli. Furthermore, the effect only obtained to neutral and not to preferred spatial areas at the dose level tested and in the apparatus used in those studies.
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  • 39
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    Psychopharmacology 37 (1974), S. 249-254 
    ISSN: 1432-2072
    Keywords: Chlorpromazine ; Rat ; Social Interaction ; Exploration ; General Motor Activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract When two animals were placed in a hole-board the number of headdips made by each rat was twice the number made when tested alone, but was the same for pairs of drugged (2 mg/kg chlorpromazine) and undrugged rats, and for pairs where only one rat was drugged. This contrasts with the reduction of headdipping produced by chlorpromazine in single animals. However, chlorpromazine still reduced general motor activity, regardless of whether the partner was drugged or not. The activity of the undrugged rats was affected by the partner's state and was lower when the partner was drugged.
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  • 40
    ISSN: 1432-2013
    Keywords: Hypothalamus ; Spike-Trains ; Correlogram/Periodogram ; Thermosensitivity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stationary spike-trains of preoptic neurons of the rat were submitted to a correlation- and spectral-analysis at normal temperature and after central warming and cooling. Correlograms and periodograms were computed which enable the elimination of stochastic signal components and the identification of the relevant periodic components. About one half of the analysed neurons showed periodic correlograms. The following three classes may be distinguished: Neurons which showed correlograms with periodicities at each applied thermal state, at only one or two thermal states and those with no recognizable periodicities at all. Relations between periodicity and the thermosensitivity of the neurons are discussed.
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  • 41
    ISSN: 1432-2072
    Keywords: Rat ; Chlordiazepoxide ; Diazepam ; Extinction ; Avoidance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In a one-way avoidance task with rats, injections of Librium (chlordiazepoxide) following avoidance acquisition resulted in prolonged resistance-to-extinction of the avoidance response. This effect occurred regardless of whether the rats had had prior experience with Librium or whether they were naive with respect to the drug. The same results were found with the same task when low doses of Valium were used. However, at a higher dosage an “extreme reaction” of either no responding or a high number of responses to extinction occurred in the naive animals. The Librium and Valium effects were compared to similar effects obtained using ethanol and hashish resin. These results indicate that the novelty hypothesis as originally stated by Amit and Baum cannot be supported because experience with the drugs prior to avoidance training did not attenuate the drug effect on avoidance.
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  • 42
    ISSN: 1432-2072
    Keywords: Ethanol ; Brain Serotonin Turnover ; Tolerance ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In rats treated acutely and chronically with ethanol, brain serotonin (5-HT) turnover was determined by measuring in the same animals the rate of accumulation of 5-HT and the rate of decline of 5-hydroxyindoleacetic acid (5-HIAA) in the brain after administration of the MAO inhibitor pargyline-HCl. In the acute study, 5-HT turnover was not altered after a single 4 g/kg oral dose of ethanol. In two separate studies, it was shown that chronic administration of ethanol in the form of a liquid diet for 32 days also did not alter brain 5-HT turnover, even when the rats had developed a significant degree of tolerance to the motor-impairing effects of ethanol. These results suggest that tolerance to ethanol is unrelated to any change in brain 5-HT turnover.
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  • 43
    ISSN: 1432-2072
    Keywords: Rat ; Successive Discrimination ; Conditioned Avoidance Response ; Nerve Impulses ; α-Methyltyrosine ; Tetrabenazine ; l-Dopa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of the administration of l-Dopa, 10 or 100 mg/kg i.p., on the α-methyltyrosine methylester HCl (α-MT; 250+50 mg/kg i. p.) or tetrabenazine (TBZ; 2 mg/kg i.p.)-induced suppression of a successive discrimination-conditioned avoidance task has been studied. It was found that administration of the high l-Dopa dose resulted in a reversal of the α-MT- or TBZ-induced suppression of the avoidance behaviour, although the discrimination was lost. Restoration of the avoidance behaviour and the correct discrimination was obtained with the low l-Dopa dose after α-MT but not after TBZ. The difference in the behavioural response to l-Dopa after α-MT as compared to the response obtained after TBZ is discussed in terms of the availability of the catecholamines formed from l-Dopa for release by the nerve impulses. Biochemical determinations of brain noradrenaline and dopamine were made in parallel. Further, a simple and reliable method for the aquisition of a successive discrimination in the rat is described.
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  • 44
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    Psychopharmacology 39 (1974), S. 237-244 
    ISSN: 1432-2072
    Keywords: Antagonism ; Fixed Interval ; Scopolamine ; Physostigmine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of this research was to determine if 2 drugs, scopolamine and physostigmine which have opposite effects on cholinergic transmission also produce opposite effects on fixed-interval (FI) performance. Scopolamine and a wide range of doses of physostigmine were administered singly and concurrently to a number of rats responding on a FI 2 min schedule. Scopolamine produced a disruption in FI curvature which could be antagonized by physostigmine, but physostigmine by itself produced no consistent change.
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  • 45
    ISSN: 1432-2072
    Keywords: Avoidance ; Drug ; Psychotropic ; Rat ; Sidman Schedule ; Sulpiride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Sulpiride, a new psychotropic drug with neuroleptic activity, was administered to rats in a Sidman avoidance schedule. Doses ranging from 1 to 80 mg/kg resulted in the animal receiving fewer shocks. This effect was not correlated with an increase of responding and seemed unrelated to the suppressing action abruptly observed at high doses (i. e. 150 to 200 mg/kg). These results differ from those classicaly obtained with other neuroleptics.
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  • 46
    ISSN: 1432-2072
    Keywords: Lithium ; Social Behaviour ; Sex ; Novelty ; Photographs ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Effects of lithium chloride on the social behaviour of male and female rats were measured in unfamiliar and familiar test situations using a photographic technique. Lithium-treated females showed an increase in body contact and a decrease in social distances in comparison with saline-treated controls in both test conditions. Males administered lithium showed increased corner occupancies in the novel test setting while in the familiar test they showed decreased body contact and increased average group social distance in comparison with the saline condition. Further tests in an exploration box confirmed that lithium decreased the general environmental responsiveness of male rats. The results are discussed with reference to the anti-aggressive effect of lithium.
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  • 47
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    Pflügers Archiv 352 (1974), S. 115-120 
    ISSN: 1432-2013
    Keywords: Urate ; Reabsorption ; Loop of Henle ; Micropuncture ; Microperfusion ; Microinjection ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Reabsorption rates for urate in the loops of Henle were measured in superficial nephrons in the rat 1. under conditions of free flow, 2. using microperfusion and 3. by a microinjection technique. 1. Under conditions of free flow distally measured TF/PUA/TF/PIn-values varied between 0.51 and 0.38 in antidiuretic rats, depending on TF/PIn (UA = both uric acid and urate, In = inulin, TF/P = concentration in tubular fluid to plasma concentration). The corresponding values in samples from end-proximal tubules were 1.06 and in urine 0.19 (U/PUA/U/PIn). 2. In microperfusion experiments of Henle loops early distal recoveries of 2-C14 urate varied between 57 and 86%, depending on the flow rates (10–40 nl/min). 3. In microinjection experiments C14 recovery in urine was about 85% when tracer solution was microinjected into endproximal tubules. From these results we conclude: 1. The main site of urate reabsorption is located in the loops of Henle. 2. This reabsorption is highly dependent on flow rates. Increase of flow rate through Henle's loop decreases urate reabsorption.
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  • 48
    ISSN: 1432-2013
    Keywords: Cardiac Hypertrophy ; Diffusion Distance of Oxygen ; High Altitude ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In rats born and staying their whole life at a simulated altitude of 3500 m a severe cardiac hypertrophy develops which is most pronounced in the right ventricle. On histological sections muscle fiber and capillary densities were counted and the surfaces occupied by muscle fibers and capillaries in the slides were estimated. Mean muscle fiber diameter and half mean distance between capillaries (diffusion distance) were obtained in the heart ventricles and were compared with those of control animals. In both ventricles an increase of the mean muscle fiber diameter occurred (true hypertrophy), being more pronounced in the right ventricle. We cannot tell whether also hyperplasia of muscle fibers occurred or not. The diffusion distance in the left ventricle of rats exposed to hypoxia was about the same as in control animals but was shorter in the right ventricle. This indicates that the total number of capillaries is higher in both ventricles of rats born in the low pressure chamber (hyperplasia of the capillaries). The shortening of the diffusion distance in the right ventricle of rats born and living their whole life at simulated high altitude was on the average smaller than that of rats exposed to simulated high altitude later in life. The physiological importance of this observation is discussed.
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  • 49
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    Pflügers Archiv 351 (1974), S. 323-330 
    ISSN: 1432-2013
    Keywords: Uricase ; Urate ; Allantoin ; Liver ; Kidney ; Microperfusion ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. In vivo uricase activity was tested in rats by injection of 2-C14 urate and measurement of the total C14 activity and the fractional activities of allantoin, allantoic acid and urea in samples of blood and urine. In control animals, 5 min after the injection, 70% of the plasma tracer was already present in the form of allantoin. No allantoic acid and urea were produced. Intestinectomy had no measurable influence on uricase activity. On the other hand, hepatectomy or ligation of the hepatic artery combined with subtotal viscerectomy did abolish uricase activity almost completely. 2. Following microinjections into proximal tubules of Ringer solution containing 2-C14 urate, urine samples during early recovery mainly contained labelled urate, whereas in later samples the fraction of labelled allantoin increased. About 12 min after the microinjection the urine of both kidneys contained equal amounts of tracer mainly in the form of allantoin. 3. When segments of proximal tubules were perfused with an equilibrium solution containing tracer amounts of C 14 urate, no urate was metabolized during its passage through the proximal tubule. 4. C 14 urate was offered from the peritubular capillaries and samples of tubular fluid were analyzed, Again, all the tracer in the tubular fluid was in the form of urate, indicating that urate is not oxidized when it is transported across the tubular cell. It is concluded from these results that: 1. The rat kidney has no significant uricase activity. 2. Urate transport in the kidney is not influenced by this enzyme. 3. The degradation of urate to allantoin takes place at extrarenal sites, mainly in the liver.
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  • 50
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    Cell & tissue research 148 (1974), S. 203-211 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Rat ; Supraoptic nucleus ; Ultrastructure ; Somatic spines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopic studies of ultrathin serial sections of the perikarya and adjacent neuropil of neurons of the supraoptic nucleus (SON) of the adult male rat revealed varying forms of two types of somatic spines. One type forms synapses with axons passing the cell, the other, without synapses, appears to serve as a buttress or clasp for adjacent neuronal and glial processes. The synapse-bearing spines lack the usual spine apparatus but contain the flocculent substance often seen in spines. The other spines do not exhibit either of these structures. These somatic spines were also seen in Golgi impregnated preparations but the types could not be distinguished. Certain axons synapse either on a somatic spine of the perikarya or penetrate the glial sheath of the neuron and synapse, usually repeatedly, on the soma in an en passant manner.
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  • 51
    ISSN: 1432-0878
    Keywords: Nerve endings ; Hair ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Palisade-shaped nerve endings of the small normal hairs of the rat snout were examined with the electron microscope (fixation by perfusion). The terminals are located inside the ‘glassy membrane’ in the area of the neck of the hair root. The 10–20 radially arranged terminal axons are in direct contact with the basement membrane of the epithelium of the external root sheath. The axons are surrounded on all sides by leaf-shaped processes of the Schwann cells. The surfaces of these cell processes are marked by numerous vesicle-like invaginations (approx. 1000 Å dia.). Transverse sections from several areas of the palisadeshaped nerve endings are compared with longitudinal sections. In the upper area ‘empty’ vesicles (approx. 500–600 Å in diameter) occur, along with electron-dense vesicles (approx. 800–1100 Å in diameter); in the middle area, the axons are distended and contain accumulations of mitochondria.
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  • 52
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Serotonin terminals ; 5,6- and 5,7-Dihydroxytryptamine ; Chemical degeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopical evidence for the existence of an important serotonergic input to the rat median eminence is presented. This evidence is based on the demonstration of degenerating nerve terminals in the external layer of the rat median eminence following the application of 5,6-dihydroxytryptamine or 5,7-dihydroxytryptamine, drugs known to exert more or less selective toxic effects on central serotonin neurons. The finding of a serotonergic innervation of the median eminence in mammals has important implications for 5-hydroxytryptamine as a modulator of synthesis and/or release of hypothalamic, hypophysiotropic hormones.
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  • 53
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    Cell & tissue research 148 (1974), S. 381-396 
    ISSN: 1432-0878
    Keywords: Placenta ; Mouse ; Syncytium ; Morphogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'origine embryologique des constituants cytologiques de la barrière placentaire chez la Souris a été mise en évidence du 8ème au 11éme jour de la gestation et la séquence des phénomènes favorisant la formation d'un syncytium trophoblastique, précisée. La barrière placentaire trilaminaire a une double origine: la couche interne provient du trophoblaste chorionique, la couche médiane syncytiale comme la couche externe dérivent du trophoblaste ectoplacentaire. Le stimulus initial de la différenciation semble résulter au 9ème jour du contact entre le trophoblaste chorionique et le mésoderme allantoïdien. Quelques heures après, on observe la réaction des cellules chorioniques, caractérisée par une augmentation importante des nucléoprotéines cytoplasmiques, puis l'apparition de globules lipidiques et enfin des propriétés de motilité. Ces cellules établissent des jonctions complexes avec le trophoblaste ectoplacentaire indifférencié qu'elles côtoient. En même temps, le métabolisme nucléaire de ces cellules ectoplacentaires semble modifié. Ultérieurement, au 10éme jour de la gestation, la disparition des membranes plasmiques latérales de ces cellules, conduit à la formation d'un syncytium par fusion de cellules au même stade d'évolution.
    Notes: Summary The morphogenesis of the different layers forming the mouse placental barrier is described during the 8th to 11th day of gestation. The timing and events leading to the formation of the syncytiotrophoblast are analyzed. Two different processes lead to the formation of the hemotrichorial placental membrane: the internal layer is formed by the chorionic trophoblast, both the intermediate syncytial layer and the external cytotrophoblast layer are derived from the ectoplacental trophoblast. The differentiation of the placental barrier begins on the 9th day of gestation by the establishment of contact between the chorionic trophoblast and the allantoic mesoderm. A few hours later, the chorionic cells show a considerable increase in cytoplasmic nucleoproteins and lipids and become ameboid. Complex cell-junctions differentiate between these chorionic cells and the adjacent ectoplacental trophoblast. On the 10th day of gestation the lateral cytoplasmic membranes disappear leading to the formation of a syncytium.
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  • 54
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    Cell & tissue research 148 (1974), S. 57-67 
    ISSN: 1432-0878
    Keywords: Prostate ; Rat ; Cyproterone ; Alterations ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The dorsal lobe and the coagulating gland of the rat prostate were studied after administration of the anti-androgenic compound Cyp A for varying periods (7–20 days). There was a general involution of the organs with macroscopic atrophy and reduced amount of secretory material. Ultrastructurally the cells were pale, contained less organelles as compared with the controls, loss of cytoplasm and reduction both of cell height and width. The major changes also included reduction of the Golgi area, the rough endoplasmic reticulum and the number of free ribosomes. Within the dorsal lobe prominent nuclear changes were found, comprising different types of intranuclear inclusions of membranous configurations. The alterations observed in the present study are similar to the changes which were found in castrated animals and are consistent with atrophy. The results are discussed in relation to the available biochemical and autoradiographic data on the different lobes.
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  • 55
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    Cell & tissue research 149 (1974), S. 91-104 
    ISSN: 1432-0878
    Keywords: Anococcygeal muscle ; Smooth muscle ; Rat ; Innervation, adrenergic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rat anococcygeus muscle, which is known from previous functional and histochemical investigations to be a smooth muscle with a dense adrenergic innervation, was studied by electron microscopic methods. The muscle was found to be organized in small bundles of 2 to 8 muscle cells, which were interconnected by desmosome-like junctions and by gap junctions. Small Schwann cell-axon complexes with 1 to 5 axons appeared to represent the functional terminal nerve pathway. Such axon complexes were located at the periphery of the small smooth muscle bundles, they never penetrated into them. A ratio of approximately 6 small axon complexes per 100 muscle cells was found. After glutaraldehyde fixation axon varicosities contained mainly small empty vesicles. After treatment with 5-hydroxydopamine and permanganate fixation mainly small vesicles with a dense core were found. The neuromuscular distances ranged from 550 to 5000 Å, with a mean of about 2600 Å. True close neuromuscular contacts at a distance below 500 Å with a fusing of basal laminae were absent. The present observations provide a morphological base for the findings of previous electrophysiological and pharmacological studies on the anococcygeal muscle.
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  • 56
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Rat ; Sex-hormones ; Ultramorphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Ultramorphometrisch wurde nach dem Verfahren von Rohr et al. (1971) die äußere Zona fasciculata von Sprague-Dawley-Ratten bei 5 Gruppen zu je 4 Tieren verglichen: Männchen, Weibchen im Diöstrus, Weibchen im Östrus, männliche und weibliche Kastraten (Kastration am 4. Lebenstag). Die Nebennierenrindenzellen der äu\eren Fasciculata sind bei Weibchen gegenüber denen normaler Männchen hypertroph: Weibchen im Diöstrus zeigen gegenüber Männchen größere Einzelzellen mit vermehrtem glattem endoplasmatischem Reticulum, erhöhten Einzel- und Gesamtvolumina der Mitochondrien sowie einem höheren Lipoidgehalt bei stärkerer Dispersion der Liposomen. Dieselben funktionsspezifischen Strukturen nehmen bei den Weibchen im Östrus noch weiter zu. Die Kastration der Weibchen am 4. Lebenstag führt zu einer Reduktion der funktionsspezifischen morphometrischen Parameter unter die Werte der Diöstrus-Tiere. Männliche Kastraten gleichen die Werte ihrer funktionsspezifischen Strukturen weitgehend denen der Weibchen im Diöstrus an. Nach Kastration am 4. Lebenstag zeigen weibliche Tiere somit etwas niedrigere morphonietrische Parameter in der äußeren Zona fasciculata als die männlichen Kastraten.
    Notes: Summary With the method of Rohr et al. (1971) the outer zona fasciculata of Sprague-Dawley-rats was compared ultramorphometrically in 5 groups of 4 animals each: males, females during diestrus, females during estrus, male and female castrates (castration on 4th day of life). Adrenal cortical cells of the outer fasciculata in females are hypertrophic in comparison with those of normal males: females during diestrus show in comparison with males larger individual cells with increased SER, increased volume of the individual mitochondrium and total volume of mitochondria as well as an increased lipoid content together with a more pronounced dispersion of liposomes. The same function-specific structures show a further increase in females during estrus. Castration of females on the 4th day of life leads to a reduction of the function-specific morphometric parameters below the values of the diestrus animals. Male castrates show adaption of the values of their function-specific structures towards those of females during diestrus. Following castration on the 4th day of life, female animals thus show somewhat lower morphometric parameters in the outer zona fasciculata than male castrates.
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  • 57
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    Cell & tissue research 149 (1974), S. 235-243 
    ISSN: 1432-0878
    Keywords: Adrenal zona glomerulosa ; Rat ; Normal ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This paper reports on an electron microscopic study of the adrenal zona glomerulosa in the normal rat, with special emphasis on the structural diversity of mitochondria in its parenchymatous cells. The mitochondria of cristae may be tubulo-vesicular, plate-like and/or straight tubular, any one mitochondrion containing one or more types of cristae. The mitochondrial features of the zona glomerulosa parenchymatous cells are attributed to the biochemical stages of aldosterone synthesis, taking place in different mitochondria of these cells.
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  • 58
    ISSN: 1432-0878
    Keywords: Neural lobe ; Mouse ; Growth and development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nerve fibres of the neurosecretory hypothalamo-hypophyseal tract were studied in embryonic C3H mouse neural lobes; at least four glands at each gestational day 15–19 were examined. Single axons and small bundles of fibres are visible at gestational days 15 and 16. By day 17 large fibre bundles penetrate between glial cells. They increase in number during the next two days. Electron-lucent and electron-dense vesicles are seen in the fibres of the 15th and 16th gestational days. In the 17–19 day-old embryos development is characterized by a successive rise in the number of the two types of vesicles. The mean diameter of the electron-lucent vesicles is approximately unchanged in all the stages examined (50 nm). The electron-dense vesicles increase in size from approximately 80–90 nm at days 15–16 to 140 nm at the 19th gestational day. By day 19 contacts between neurosecretory fibre terminals and the outer basement membrane of internal and peripheral capillaries are occasionally observed. The possibly adrenergic nature of a few terminals contacting peripheral vascular structures in 17 and 18 day-old embryos is suggested.
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  • 59
    ISSN: 1432-0878
    Keywords: Pinealocyte-resembling cells ; Habenular region ; Sympathetic nerve fibres ; Ontogenetic development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cells of the pineal gland, the pineal stalk, and the lamina intercalaris contain 5-HT and are innervated by sympathetic nerve fibres. These peripheral nerve fibres continue rostrally from the lamina intercalaris and run into the central nervous tissue of stria medullaris and the habenular nuclei. Pharmacological treatment to increase the cellular 5-HT content revealed that the sympathetic fibres are in close relation to yellow fluorescent cells embedded in the brain tissue. These yellow fluorescent cells develop very late in the ontogenetic development (three weeks or more postnatally) and are preceded by ingrowth of sympathetic fibres into the brain tissue. The results support the hypothesis that the cells found in the habenular region are of pinealocyte rather than neuronal nature, but it is possible that they differ in certain aspects from the cells of the pineal gland proper.
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  • 60
    ISSN: 1432-0878
    Keywords: Hypothalamo-neurohypophysial system ; Rat ; Granule distribution ; Electron microscopy, morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Neurohypophyse und die neurosekretorischen hypothalamischen Kerngebiete von normalen männlichen und weiblichen Ratten, von trächtigen und durstenden Tieren wurden elektronenmikroskopisch und morphometrisch mit der Fragestellung untersucht, ob sich in den Häufigkeitsverteilungen der mittleren Granula-Durchmesser, bezogen auf die Anzahl der Axone, eine zweigipflige Verteilung ergibt. Bei Kontrolltieren zeigen die Perikarya des Nucleus supraopticus zahlreichere und größere Granula als die Zellen des Nucleus paraventricularis, wobei der Unterschied in den Durchmessern der Granula bei den weiblichen Tieren ausgeprägter ist als bei den männlichen. Beide Kontrollgruppen zeigen in der Neurohypophyse ein zweigipfliges Verteilungsmuster der Granula, wobei die beiden Gipfel bei den männlichen Kontrollen dichter beieinander liegen als bei den weiblichen. Bei den trächtigen Tieren weisen beide Kerngebiete Zeichen gesteigerter Aktivität auf und die Granula in den Zellen des Nucleus paraventricularis sind deutlich größer als bei Kontrolltieren. Zu Beginn der Tragzeit werden relativ große, wahrscheinlich vasopressinhaltige Granula in der Neurohypophyse gespeichert, während sich im letzten Drittel der Tragezeit die beiden Populationen dort nicht mehr unterscheiden lassen. Nach 48 Std. Wasserentzug erscheinen beide hypothalamischen Kerne aktiviert. Auffallend ist, daß die Granula im Nucleus supraopticus deutlich kleiner sind als bei Kontrolltieren. Entsprechend fehlen in der Neurohypophyse große Granula, während Axone mit kleinen Granula vermehrt sind. Nach zehntägiger Durstperiode lassen sich im Nucleus supraopticus, neben sehr typischen morphologischen Veränderungen, morphometrisch ebenfalls deutlich kleinere Granula nachweisen. Im Hypophysenhinterlappen dieser Versuchsgruppe sind die granulahaltigen Axone sehr stark vermindert, und in der Häufigkeitsverteilung fehlen die Granula mit großem Durchmesser während der dem Oxytocin zugeordnete Gipfel unverändert erscheint. In Verbindung mit den elektronenmikroskopischen Befunden lassen sich also aus den Verschiebungen der Verteilungsmuster zwischen den sechs Versuchsgruppen die Granula mit kleinerem Durchmesser oxytocinhaltigen Axonen zuordnen und Granula mit größerem Durchmesser zu den Endigungen, die Vasopressin enthalten. Die morphometrischen Befunde in den neurosekretorischen hypothalamischen Kerngebieten bestätigen diese Zuordnung. Die elektronenmikroskopischen und morphometrischen Befunde werden besonders im Hinblick auf die Hormonverschiebungen zwischen dem “reserve pool” und den “easily releasable pool” diskutiert.
    Notes: Summary A morphometric evaluation of electron micrographs has been carried out from neurosecretory terminals in the neurohypophysis and from the supraoptic and paraventricular nuclei in normal male and female rats as well as in pregnant and water deprived rats. The task of this investigation was to find out whether frequency distribution diagrams of the mean diameter of the neurosecretory granules, plotted versus the number of axons, reveal a grossly bimodal distribution. In normal rats the nerve cells of the nucleus supraopticus (S.O.N.) show more numerous and larger granules than the cells of the nucleus paraventricularis (P.V.N), this difference with respect to the diameter being more pronounced in female than in male animals. In the posterior pituitary lobes the neurosecretory granules exhibit a bimodal distribution, the second peak being situated more closely to the first one in male controls. In pregnant animals both nuclei appear to be activated, and the granules of P.V.N. are distinctly larger as compared to those of female control animals. In early pregnancy larger, i.e. presumably vasopressin-containing granules are stored in the neurohypophysis, while in the last phase before delivery oxytocin-containing neurons and vasopressin-containing ones cannot be differentiated any more. After 48 hrs of thirst both hypothalamic nuclei exhibit signs of increased activation, the diameters of the granules in the S.O.N. being distinctly smaller than in normals. In the neurohypophysis granules with large diameters are lacking, while axons with small granules are more frequent. In the S.O.N. of animals, water deprived for 10 days the diameters of the granules are smaller than normal and in the