Anoxia-Reoxygenation in Cultured Endothelial Cells: Effects of Fructose Diphosphate and Captopril

Abstract

Cultured rat aortic endothelial cells were morphologically and immunologically characterized before incubation under anoxic conditions for 120 minutes. Cell samples were reoxygenated for 10, 30, and 60 minutes as a model of anoxia-reperfusion injury. The effects of anoxia-reoxygenation were evaluated by measurements of membrane microviscosity, intracellular Ca2+ content, release of 51Cr, and uptake of trypan blue. Membrane microviscosity decreased from 2.03 ± 0.17 poise before anoxia to 1.72 ± 0.22 poise after 120 minutes of anoxia, with a further decrease to 1.54 ± 0.29 poise after 60 minutes of reoxygenation. Release of 51Cr correlated negatively with the decrease in membrane microviscosity and rose from 7.14% ± 0.4% to 12.16% ± 2.79% after anoxia and to 27.17% ± 2.59% after 60 minutes of reoxygenation. Intracellular Ca2+ content and uptake of trypan blue showed no noticeable change during anoxia but they increased significantly during reoxygenation. Addition of fructose-1,6-diphosphate to the anoxic incubation medium partly prevented the change in microviscosity and significantly reduced the release of 51Cr and the uptake of Ca2+ and trypan blue. Captopril exerted similar but less potent effects to those of fructose-1,6-diphosphate.