Antagonistic effect of captopril on activation and injury of vascular endothelial cells induced by lipopolysaccharide

AIM: To investigate the antagonistic action of Captopril (Cap) on the activation and injury of human umbilical vascular endothelial cells (HUVECs) induced by lipopolysaccharide(LPS) and the possible mechanisms. METHODS: After 18 h exposure of the cultured HUVECs to LPS (1 mg/L), or LPS (1 mg/L) plus Cap at the concentration of 10^-7mol/L, 10^-5mol/L and 10^-3mol/L, the expression of vWF protein in the conditioned media was tested by enzyme-linked immunosorbent assay (ELISA), the expression of ICAM-1 protein in HUVECs was determined by indirect immunofluorescence technique with flow cytometry as well. In addition, the expression of TNFα mRNA was determined by in situ hybridization. RESULTS: The results of ELISA and indirect immunofluorescence technique showed that exposure to LPS at a concentration of 1 mg/L led to a significant increase in the vWF and ICAM-1 expression in HUVECs as compared to the control (P＜0. 05), whereas they were somewhat decreased when exposed to Cap at three increasing concentrations mentioned above, especially in the Cap (10^-3mol/L) plus LPS group (P＜0.05). Cap inhibited vWF secretion and ICAM-1 expression of HUVECs caused by LPS in a concentration-dependent manner. In situ hybridization revealed that the expression of TNFα mRNA was inhibited by Cap both in a concentration of 10^-3mol/L, and in a lower concentration of 10^-5mol/L. CONCLUSION: Cap antagonizes the activation and injury of HUVECs induced by LPS, which may be related to the decrease in TNFα mRNA expression.