Objective To observe the antagonistic effects of metallothionein (MT) on homocysteine(Hcy) induced endothelial cell injury
and
lipid peroxidation. Methods Human
vascular endothelial cells (VECs) were cultured.The survival rate of VECs was calculated by trypan blue exclusion,lactate dehydrogenase (LDH) leakage was measured by NADH oxidation. Intracellular contents of MT and malondialdehyde (MDA) were assayed by ~ 109 Cd-hemoglobin saturation method and TBA reaction,respectively.Activities of SOD and GSH-Px were measured by chemical method. Results Hcy increased LDH leakage and MDA contents of cultured VECs,and decreased viabilities of cultured VECs and activities of SOD and GSH-Px in VECs.Exogenous MT (5×10~ -8 mol·L~ -1 ) could inhibit Hcy-induced VECs injury.The survival rate of VECs in MT(5×10~ -8 mol·L~ -1 ) plus Hcy(1.0 mmol·L~ -1 ) group increased by 8.0%(P<0.05) and LDH leakage decreased by 24.4%(P<0.01),and activities of SOD and GSH-Px increased by 24.2%(P<0.01) and 16.2%(P<0.05) respectively,compared with Hcy group.MT production of cultured VECs was induced by preincubation of thrombin.MT contents in thrombin group increased by 44.7%(P<0.01),compared with control group.The survival rate of cultured VECs in thrombin plus Hcy group increased by 9.1% (P<0.05),LDH leakage of cultured VECs decreased 34.0%(P<0.01),and activities of SOD and GSH-Px of cultured VECs increased 17.4%(P<0.05)and 11.6%(P<0.01) respectively,compared with Hcy group. Conclusion Hcy induces injury of cultured VECs and decreases antioxidation of cultured VECs.Exogenous or endogenous MT all can antagonise VEC injuries by Hcy.