[Comparative evaluation of the cytotoxic effect of hydrogen peroxide and tumor necrosis factor alpha on nonischemic and ischemic endothelial cells].

We studied cytotoxic effects (CTE) induced in confluent cultures of human umbilical vein endothelial cells (HUVEC) by initiators of free-radical reactions (FRR): H2O2 (10(-6)-10(-9) M), recombinant human tumor necrosis factor-[symbol; see text] (TNF-alpha, 0.05-100 ng/ml), and a combination of TNF-alpha with low-density lipoproteins (LDL, 100 microgram/ml). HUVEC were incubated with these substances for 6 or 24 h in parallel tests performed under aerobic (CO2-incubator) and ischemic conditions (a mixture of 95% N2 + 5% CO2 in RPMI-1640 medium containing no substrate additives, growth factor or protein).