Brain Capillaries (brain + capillary)

Distribution by Scientific Domains
Life Sciences75%

Terms modified by Brain Capillaries

  • brain capillary endothelial cell
    		•

    Selected Abstracts

    Alzheimer-like changes in protein kinase B and glycogen synthase kinase-3 in rat frontal cortex and hippocampus after damage to the insulin signalling pathway

    JOURNAL OF NEUROCHEMISTRY, Issue 4 2006
    Melita Salkovic-Petrisic
    Abstract The insulin-resistant brain state is related to late-onset sporadic Alzheimer's disease, and alterations in the insulin receptor (IR) and its downstream phosphatidylinositol-3 kinase signalling pathway have been found in human brain. These findings have not been confirmed in an experimental model related to sporadic Alzheimer's disease, for example rats showing a neuronal IR deficit subsequent to intracerebroventricular (i.c.v.) treatment with streptozotocin (STZ). In this study, western blot analysis performed 1 month after i.c.v. injection of STZ showed an increase of 63% in the level of phosphorylated glycogen synthase kinase-3,/, (pGSK-3,/,) protein in the rat hippocampus, whereas the levels of the unphosphorylated form (GSK-3,/,) and protein kinase B (Akt/PKB) remained unchanged. Three months after STZ treatment, pGSK-3,/, and Akt/PKB levels tended to decrease (by 8 and 9% respectively). The changes were region specific, as a different pattern was found in frontal cortex. Structural alterations were also found, characterized by ,-amyloid peptide-like aggregates in brain capillaries of rats treated with STZ. Similar neurochemical changes and cognitive deficits were recorded in rats treated with i.c.v. 5-thio- d -glucose, a blocker of glucose transporter (GLUT)2, a transporter that is probably involved in brain glucose sensing. The IR signalling cascade alteration and its consequences in rats treated with STZ are similar to those found in humans with sporadic Alzheimer's disease, and our results suggest a role for GLUT2 in Alzheimer's pathophysiology. [source]

    Distinct spatio-temporal expression of ABCA and ABCG transporters in the developing and adult mouse brain

    JOURNAL OF NEUROCHEMISTRY, Issue 1 2005
    Masanori Tachikawa
    Abstract Using in situ hybridization for the mouse brain, we analyzed developmental changes in gene expression for the ATP-binding cassette (ABC) transporter subfamilies ABCA1,4 and 7, and ABCG1, 2, 4, 5 and 8. In the embryonic brains, ABCA1 and A7 were highly expressed in the ventricular (or germinal) zone, whereas ABCA2, A3 and G4 were enriched in the mantle (or differentiating) zone. At the postnatal stages, ABCA1 was detected in both the gray and white matter and in the choroid plexus. On the other hand, ABCA2, A3 and A7 were distributed in the gray matter. In addition, marked up-regulation of ABCA2 occurred in the white matter at 14 days-of-age when various myelin protein genes are known to be up-regulated. In marked contrast, ABCA4 was selective to the choroid plexus throughout development. ABCG1 was expressed in both the gray and white matters, whereas ABCG4 was confined to the gray matter. ABCG2 was diffusely and weakly detected throughout the brain at all stages examined. Immunohistochemistry of ABCG2 showed its preferential expression on the luminal membrane of brain capillaries. Expression signals for ABCG5 and G8 were barely detected at any stages. The distinct spatio-temporal expressions of individual ABCA and G transporters may reflect their distinct cellular expressions in the developing and adult brains, presumably, to regulate and maintain lipid homeostasis in the brain. [source]

    Tissue Distribution of P-Glycoprotein in Cats

    ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2009
    S. Van Der Heyden
    Summary Permeability glycoprotein (P-gp) is a membrane-bound efflux pump that exports various substances out of the cell. Variations in P-gp expression play an important role in susceptibility to toxic substances, drug efficacy and disease risk. In the present study, the distribution of the MDR1 -gene product P-gp was determined in normal tissues of domestic shorthair cats using immunohistochemistry. Two monoclonal antibodies C494 and C219 were used, recognizing a different epitope on the human P-gp molecule. A consistent positive immunolabelling was obtained. The tissue distribution and cellular locations with antibody C494 were similar to those in man and dogs; with liver, colon, adrenal cortex and brain capillaries being consistently and intensely labelled. However, the immunolabelling in the kidney was in contradiction to man and dogs. The C219 antibody seems to react with a specific form of P-gp, only expressed in feline tissues with a barrier function, i.e. endothelia of the brain, testes and ovaries, and intestinal epithelial cells in contact with the lumen. [source]

    ,v -Integrin antagonist EMD 121974 induces apoptosis in brain tumor cells growing on vitronectin and tenascin

    INTERNATIONAL JOURNAL OF CANCER, Issue 5 2002
    Takashi Taga
    Abstract Orthotopic brain tumor growth is inhibited in athymic mice by the daily systemic administration of the ,v -integrin antagonist EMD 121974. This compound, a cyclic RGD-penta-peptide, is a potent inhibitor of angiogenesis, which induces apoptosis of growing endothelial cells through inhibition of their ,v -integrin interaction with the matrix proteins vitronectin and tenascin. Here we show that EMD 121974 also induces apoptosis in the ,v -integrin-expressing tumor cell lines U87 MG and DAOY by detaching them from vitronectin and tenascin, matrix proteins known to be essential for brain tumor growth and invasion. These matrix proteins are shown to be produced by the brain tumor cells in vitro and in vivo. Furthermore, only tumor cells expressing ,v -integrins responded to the treatment with EMD 121974, after xenotransplantation into the forebrain of nude mice, supporting the importance of tumor cell-matrix interactions in tumor cell survival in the brain. Thus, the ,v -antagonist EMD 121974 suppresses brain tumor growth through induction of apoptosis in both brain capillary and brain tumor cells by preventing their interaction with the matrix proteins vitronectin and tenascin. The dual action of this peptide explains its potent growth suppression of orthotopically transplanted brain tumors. © 2002 Wiley-Liss, Inc. [source]