Atsushi Miyamoto, Tomoko Matsuyama, Shigeru Ishiguro and Akira Nishio
Department of Veterinary Pharmacology, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan
Abstract: In a radioligand binding study using bovine coronary artery endothelial cell membranes, captopril changed a single bradykinin (BK) binding site (Kd=1.77╩nM, Bmax=60.2╩fmol/mg protein) to high- (Kd=0.68╩pM, Bmax=17.7╩fmol/mg protein) and low- (Kd=1.00╩nM, Bmax=72.5╩fmol/mg protein) affinity binding sites. This effect was reversed by GppNHp. Captopril also enhanced BK-induced endothelium-dependent relaxation in saponin-treated coronary rings, and GppNHp partially suppressed this enhancement. These results suggest that captopril may affect BK receptors that couple to G-proteins.
Keywords: Bradykinin, Captopril, Coronary artery
Copyrightę The Japanese Pharmacological Society 2000
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