Dual proapoptotic and pronecrotic effect of hydrogen peroxide on human umbilical vein endothelial cells

Human umbilical vein endothelial cells were exposed in culture to hydrogen peroxide (H2O2), keeping them close to physiological conditions (high cell density, high serum content, H2O2 concentration not over 500 µM). Cell viability was assessed by flow cytometry using simultaneous staining with the fluorescent dye PO-PRO-1 to detect early apoptotic cells and DRAQ7 to detect late apoptotic and necrotic cells. The data obtained suggest that the primary mechanism of the cytotoxic response to H2O2 is apoptosis. The critical concentration of H2O2 causing death in a dense monolayer is 250 µM. Lower H2O2 concentrations (up to 200 µM) cause death of individual cells. The population of endothelial cell retains viability and response to calcium activating agonists does not change compared to control cells. © 2016, Pleiades Publishing, Ltd.