Aim To investigate the effects of hydrogen sulfide on ox-LDL-induced apoptosis in human umbilical vein endothelial cells(HUVEC) and the mechanisms involved.Methods The HUVEC were incubated with ox-LDL for 24 hours after treatment with NaHS at different concentrations(25,50,100,200 μmol/L) for 24 hours or for different incubation time(6,12,24 hours) at the concentration of 50 μmol/L.The apoptotic alterations of HUVEC were observed by Hoechst 33258 staining and flow cytometry(FCM),respectively.The change of mitochondrial membrane potent...