Capillary endothelial cells

Pericytes are mural cells which stabilise capillaries and control functions of capillary endothelial cell properties. 

ADM may evolve over several years, the extent of fiber atrophy provides an important indication of the chronicity of muscle degeneration. Acute muscle necrosis and phagocytosis give some indication as to how active the disease is at the time of biopsy. In most biopsies from ADM patients, the inflammatory cell foci are perivascular and perimysial rather than endomysial and are dominated by B-lymphocytes. The ratio of T4 lymphocytes (helper cells) to T8 lymphocytes (cytotoxic) generally indicates a predominance of the former. As in JDM, this is consistent with humoral mechanisms of cell damage, and vascular involvement is also apparent in the form of capillary endothelial cell abnormalities (tubular arrays) and duplication of basal lamina. Loss of myofibrillar ATPase from the central portions of fibers is a common prelude to muscle necrosis. 

Bassingthwaighte JB, Wang CY, Chan IS. Blood-tissue exchange via transport and transformation by capillary endothelial cells. Circ Res 1989 65 997-1020. 

Jarasch, E.D., Bruder, G. and Held, H.W. (1986). Significance of xanthine oxidase in capillary endothelial cells. Acta Physiol. Scand. (Suppl.) 548, 39-46. 

Blood-brain barrier A physicochemical barrier formed by astrocytes and capillary endothelial cells. It prevents toxic chemicals from entering CNS neurons from the systemic blood circulation. 

Fig. 15.3 D iagram showing a longitudinal cross-section of the blood-brain barrier, with the brain capillary endothelial cells sealed by the tight junctions and surrounded by pericytes and astrocyte foot processes. These cellular components of the BBB are separated by a basement membrane.

Fig. 15.5 D iagram showing some of the nutrient and drug transport processes associated with the brain capillary endothelial cells that form the BBB. Local transporters in the luminal or/and abluminal membranes are depicted as filled circles and ones whose location is more questionable or that are present at the BBB are depicted in open circles. GLUT1, LAT1, MCT1, oatp2 are present on both the luminal and abluminal membranes. This diagram shows that transport may be unidirectional or bidirectional.

The presence at the BBB of members of the multidrug resistance-associated protein (MRPs) family, whose members preferentially transport anionic compounds, is still controversial. The seven members of the MRP family belong, like P-gp, to the ATP-binding cassette (ABC) protein superfamily. Mrpl has been found at the BBB in isolated rat brain capillaries, primary cultures of brain capillary endothelial cells and in immortalized capillary endothelial cells, but not in human brain capillaries [59]. Another member, MRP2 has been found at the luminal membrane of the brain endothelial cells [60]. However, further studies are required to show that there are MRP transporters at the BBB (Figure 15.5). As for P-gp, a functional Mrpl was found in primary cultured rat astrocytes [56] and it has been shown to take part in the release of glutathione disulfide from brain astrocytes under oxidative stress [61]. 

The first gene-knockout mouse to become available was a mouse lacking detectable P-gp in the brain capillary endothelial cells. This has been used to elegantly... 

Betz AL, Firth JA, Goldstein GW. Polarity of the blood-brain barrier distribution of enzymes between the luminal and antiluminal membranes of brain capillary endothelial cells. Brain Res 1980 192 17-28. 

Brown WJ. The large apparent work capability of the blood-brain barrier a study of capillary endothelial cells in brain and other tissues of the rat. Ann Neurol 1977 1 409-417. 

Roberts C, Chen CS, Mrksich M, Martichonok V, Ingber DE, Whitesides GE (1998) Using mixed self-assembled monolayers presenting RGD and (EG)3OH groups to characterize long-term attachment of bovine capillary endothelial cells to surfaces. J Am Chem Soc 120 6548-6555... 

Brain capillary endothelial cells and some neurons also express a Na+-dependent D-glucose symporter, SGLT1 91... 

Brain capillary endothelial cells and some neurons also express a Na+-dependent D-glucose symporter, SGLT1. SGLT1 (SLC5A1) was the first characterized of the large SLC5 family of Na-dependent symporters (SSSF) which transport various solutes and ions into cells [77, 78]. SGLT1 is found mainly in the intestine, trachea,... 

CNS development are employed for the same purpose in the PNS. PNS microglia-like cells, like microglia in the CNS, are bone-marrow-derived and have a similar repertoire of responses to activation [2], Both oligodendroglia and Schwann cells speed axonal action potential propagation by assembling and maintaining myelin. Capillary endothelial cells linked by tight junctions restrict entry of polar molecules into the PNS, as into the CNS [3],... 

An interesting feature of many cells is the permanent presence on the plasma membrane of flask-shaped regions termed caveolae. They are abundant in certain capillary endothelial cells, and appear to have a role in cholesterol binding, although many other functions have been suggested [62]. 

Zhang, Y., Schuetz, J.D., Elmquist, W.F. and Miller, D.W. (2004) Plasma membrane localization of multidrug resistance-associated protein homologs in brain capillary endothelial cells. Journal of Pharmacology and Experimental Therapeutics, 311, 449-455. 

Figure 14.2 Phase contrast microscopic images of conditionally immortalized cells forming the inner blood-retinal barrier (A) and time-course of [3H] adenosine uptake by TR-iBRB cells (B). A Conditionally immortalized rat retinal capillary endothelial cell line TR-iBRB, retinal pericyte cell line TR-rPCT and Muller cell line TR-MUL. B The [ H]adenosine (14 nM) uptake was performed at 37°C in the presence (closed circle) or absence (open circle) of Na+.

Immunohistochemical study ND not determined GLUT1 facilitative glucose transporter MCT1 monocarboxylate transporter CRT creatine transporter LAT1 L-type amino acid transporter TAUT taurine transporter ENT equilibrative nucleoside transporter Oatp organic anion-transporting polypeptide PAH p-aminohippuric acid RUI retinal uptake index TR-iBRB rat retinal capillary endothelial cells. 

K. Hosoya, M. Tomi, S. Ohtsuki, H. Takanaga, M. Ueda, N. Yanai, M. Obinata, and T. Terasaki. Conditionally immortalized retinal capillary endothelial cell lines (TR-iBRB) expressing differentiated endothelial cell functions derived from a transgenic rat. Exp. Eye Res. 72 163-172 (2001). 

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