Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Rat  (2)
  • Springer  (2)
  • International Union of Crystallography (IUCr)
  • 1
    ISSN: 1432-0738
    Keywords: Aluminum ; Toxicokinetics ; Rat ; Parenterals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The toxicokinetics of aluminum (Al) in male Wistar rats was studied after single intragastric (IG) doses of 1000 and 12000 μg Al/kg and intravenous (IV) doses of 10, 100, 1000, and 12000 μg Al/kg. Serial blood samples, daily samples of urine and feces as well as brain, liver, kidney, spleen, quadriceps muscle, and femur samples were collected. Al was measured by atomic absorption spectrometry. Al blood profiles after IV doses were adequately described by a two-compartment open model. Al toxicokinetics was dose dependent and appeared to plateau at 12000 μg/kg. At IV doses between 10 and 1000 μg/kg the terminal half-life of elimination from whole blood (t1/2β) increased from 29.9±7.8 to 209.3±32.6 min, and the total body clearance (CL) decreased from 2.45±0.64 to 0.28±0.03 ml min−1 kg−1. Following an IV bolus of 10 and 100 μg/kg the administered Al was recovered completely from urine (94.4%±9.9% and 98.5%±3.2%). Twenty-nine days after the IV dose of 1000 μg/kg daily renal excretion decreased to baseline values while only 55.1%±8.0% of the dose was excreted. Nineteen days after the single IV dose of 1000 μg/kg Al accumulated in liver (28.1±7.7 versus 1.7±0.5 μg/g of control rats) and spleen (72.5±21.1 versus 〈0.4 μg/g). After the single 1000 μg/kg IG dose no absorption of Al was detectable. The IG dose of 12000 μg/kg resulted in a maximum blood Al level of 47.9±12.4 μg/l after 50 min. The blood concentration time curve fitted a one-compartment open model with a half-life of absorption of 28.2±3.6 min and a t1/2β of 81.2±20.2 min. Cumulative renal Al excretion was 0.18%±0.10% of the dose and oral bioavailability was 0.02%. Seventeen days after the 12000 μg/kg IG dose the Al content in femur samples was increased (2.7±1.3 versus 0.6±0.4 μg/g). In no case was fecal elimination of incorporated Al observed.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1106
    Keywords: Electrophysiology ; Medulla oblongata ; Spinal cord ; Interneurons ; Respiratory control ; Intracellular labelling ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Upper cervical inspiratory neurons form a distinct neuronal column located near the lateral edge of the intermediate grey matter in the rostral spinal segments. Previous studies conducted in cats have demonstrated synaptic inputs to these neurons from several respiratory related regions of the medulla, and long descending axonal projections mainly towards the motoneurons supplying the intercostal muscles. The aim of this study was to examine the electrophysiological and morphological properties of this propriospinal system in the rat. Extracellular recordings were made from 127 cervical inspiratory units, mainly in the C1 and C2 segments. Eighty-two percent could be antidromically activated from the C7/C8 border. No evidence of monosynaptic connection was obtained by cross-correlating the activity of some of these units with the discharge of the phrenic nerve. Intracellular recordings were made from seven neurons, three of which were labelled with biotinamide (neurobiotin). Long “survival times” after intracellular injections (up to 23 h) resulted in staining of axons for long distances, at least to the C5 segment. Each of the three labelled axons issued only one short collateral which arborized in the region of the phrenic nucleus. These results demonstrate that upper cervical inspiratory neurons in the rat have features similar to those previously described in the cat, including only a limited projection to the phrenic nucleus. In addition, this study provides the first morphological identification of these neurons.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...