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  • 1
    ISSN: 1432-0533
    Keywords: Key words Protamine ; Blood-brain barrier ; Endogenous albumin ; Immunocytochemistry ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The cellular mechanisms of blood-brain barrier (BBB) opening to endogenous albumin in the mouse brain after intracarotid infusion of solutions of protamine free base (PB) or protamine sulfate (PS) were studied using quantitative immunocytochemistry. Ultrathin sections of brain samples embedded at low temperature in Lowicryl K4M were exposed to anti-mouse albumin antiserum followed by protein A-gold. Using morphometry, the density of immunosignals (gold particles per μm2) was recorded over four compartments: vascular lumen, endothelial profiles, subendothelial space (including the basement membrane), and brain parenchyma (neuropil). In addition, the adsorption of endogenous albumin evidenced by the number of gold particles per μm of the endothelial luminal plasmalemma was quantitatively evaluated. In the applied experimental conditions, PB was found to be strongly cytotoxic as indicated by the appearance of rapid degenerative changes and the disruption of the endothelial lining with concomitant clumping of the blood plasma. The action of PS was milder, offering a better opportunity for detailed ultrastructural and morphometric examination of brain samples during consecutive steps of PS action (2, 5, 10 and 30 min). As early as 10 min after infusion of PS solution, the adsorption of blood plasma albumin to the endothelial luminal surface was increased 2.5 times. Simultaneously, the immunolabelling of the endothelial profiles and subendothelial space was significantly increased. These results suggest that BBB disruption occurs through enhanced adsorption of albumin or albumin-protamine complexes to the luminal plasmalemma, followed by transendothelial vesicular transport, rather than through modification of interendothelial junctional complexes. This process appears to be focally disseminated throughout the cerebral vascular network and declines at 30 min following infusion of PS solution.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0533
    Keywords: Protamine ; Blood-brain barrier ; Endogenous albumin ; Immunocytochemistry ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The cellular mechanisms of blood-brain barrier (BBB) opening to endogenous albumin in the mouse brain after intracarotid infusion of solutions of protamine free base (PB) or protamine sulfate (PS) were studied using quantitative immunocytochemistry. Ultrathin sections of brain samples embedded at low temperature in Lowicryl. K4M were exposed to anti-mouse albumin antiserum followed by protein A-gold. Using morphometry, the density of immunosignals (gold particles per μm2) was recorded over four compartments: vascular lumen, endothelial profiles, subendothelial space (including the basement membrane), and brain parenchyma (neuropil). In addition, the adsorption of endogenous albumin evidenced by the number of gold particles per μm of the endothelial luminal plasmalemma was quantitatively evaluated. In the applied experimental conditions, PB was found to be strongly cytotoxic as indicated by the appearance of rapid degenerative changes and the disruption of the endothelial lining with concomitant clumping of the blood plasma. The action of PS was milder, offering a better opportunity for detailed ultrastructural and morphometric examination of brain samples during consecutive steps of PS action (2, 5, 10 and 30 min). As early as 10 min after infusion of PS solution, the adsorption of blood plasma albumin to the endothelial luminal surface was increased 2.5 times. Simultaneously, the immunolabelling of the endothelial profiles and subendothelial space was significantly increased. These results suggest that BBB disruption occurs through enhanced adsorption of albumin or albumin-protamine complexes to the luminal plasmalemma, followed by transendothelial vesicular transport, rather than through modification of interendothelial junctional complexes. This process appears to be focally disseminated throughout the cerebral vascular network and declines at 30 min following infusion of PS solution.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-0533
    Keywords: Key words Aging ; Blood-brain barrier ; Horseradish peroxidase ; Senescence-accelerated mouse ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ultrastructural features of microvessels showing increased permeability to intravenously injected horseradish peroxidase (HRP) were examined in the olfactory bulbs of senescence-accelerated prone mice (SAMP8), which showed age-related deficits in learning and memory, and senescence-accelerated resistant mice (SAMR1), which did not show the age-related deficits. HRP was visualized with tetramethyl benzidine (TMB) and diaminobenzidine (DAB) for light and electron microscopic examination, respectively. In the olfactory bulbs of 13-month-old SAMP8 mice, the staining reaction with TMB for HRP appeared in the neuropil of central area (granule cell layer and subependymal layer), in the pia mater and in the vascular wall. Some vessels located in the central area showed several changes observed at the ultrastructural level. The cytoplasm of the endothelial cells, especially in the arterioles, was segmentally thickened and contained numerous vesicles and vacuoles, some of which were HRP positive. The endothelial cell surface was occasionally undulated with microvillous protrusions. Membranous inclusions within the basal lamina, suggesting the cellular (presumably pericytal) degeneration, were frequently observed, especially in venules. The collagen deposits were occasionally observed in the subendothelial space of some vessels. Perivascular cells with vacuolated inclusions or lipid-like droplets were present around some vessels in the central area of the olfactory bulbs of aged SAMP8 mice. On the other hand, in the microvessels located in the areas negative for HRP-TMB reaction, except the vessel walls, the cytoplasm of the endothelial cells with smooth luminal surface was flattened and some vesicles located there contained HRP-DAB reaction product. Weak staining reaction with TMB for HRP appeared also in the central area of the olfactory bulbs of 3-month-old SAMP8 mice and 3- and 13-month-old SAMR1 mice. The cytoplasm of the endothelial cells in the olfactory bulbs of these mice was focally thickened and contained some cytoplasmic vesicles. Occasionally, the endothelial cell surface was moderately undulated with few microvillous protrusions. Membranous inclusions within the basal lamina were not observed in these animals. These findings indicate that the endothelial cells and pericytes in some vessels located in the central area of the olfactory bulb of aged SAMP8 mice, which show staining reaction with TMB for HRP, are ultrastructurally changed, suggesting their altered functions.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0167-4943
    Keywords: Aging ; Blood-brain barrier ; Human serum albumin ; Intravenous injection ; Mouse olfactory bulb
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0167-4943
    Keywords: Aging ; Blood-brain barrier ; Human serum albumin ; Memory deficit ; Senescence accelerated mouse (SAM)
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Medicine
    Type of Medium: Electronic Resource
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