抄録
The relationship between sulthydryls and cGMP has been observed in several biological processes. Captopril is a sulfhydryl-containing angiotensin converting enzyme (ACE) inhibitor, that decreases PGI2 production in cultured human vascular endothelial cells. Enalapril does not appear to have this property. The role of cyclic GMP (cGMP) and sulthydryls in the regulatory mechanisms in captopril-induced PGI2 production and Ca++ kinetics was investigated. Brady-kinin and Ca ionophore A23187 enhanced PGI2 production, and increased the cytosolic free Ca++ concentration ([Ca<++gtn]i). It was observed that 8-bromo cGMP increased intracellular cGMP concentration ([Ca++]i), and decreased PGI2 production without changing [Ca++]i. Sulthydryl containing compounds such as captopril. N-acetylcysteine and glutathione decreased PGI2 production via increased [cGMP]i. Enalapril, an ACE inhibitor without sulthydryls, has no effect on PGI2 production, [Ca<++gtn]i and [cGMP]i. These results suggested that the presence of sulfhydryl groups is an important factor in the ability of vasoactive substances to induce PGI2 production.
