Gamma-glutamyl-transpeptidase (GGTP) and NA+K(+)-ATPase activities in different subpopulations of cloned cerebral endothelial cells: responses to glial stimulation.
Glial stimulation of Na+K(+)-ATPase and gamma-glutamyl-transpeptidase was taken as parameter for blood brain barrier function in cloned cerebral endothelial cells of different phenotypes. In type I cells ("cobblestone" phenotypus) gamma-glutamyl-transpeptidase activity increased 10-12 fold and Na+K(+)-ATPase activity was 2-fold increased after glial stimulation. In type II cells ("spindle-form" phenotype) gamma-glutamyl-transpeptidase was only 2-fold increased, whereas Na+K(+)-ATPase was even depressed. K(+)-(86Rb) uptake was twice as high in type I cells. These data indicate that type I cells are involved in blood brain barrier function.
Bauer
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Institute f. Molecular Biology, Austrian Academy of Sciences, Salzburg.
Tontsch
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Amberger
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Bauer
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D000818:Animals; D001921:Brain / Q000201:enzymology*; D002417:Cattle; D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D004727:Endothelium / Q000201:enzymology; D066298:In Vitro Techniques; D009457:Neuroglia / Q000502:physiology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
D005723:gamma-Glutamyltransferase; D000254:Sodium-Potassium-Exchanging ATPase