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ﾊnM, Bmax=60.2ﾊfmol/mg protein)
to high- (Kd=0.68ﾊpM, Bmax=17.7ﾊfmol/mg protein) and
low- (Kd=1.00ﾊnM, Bmax=72.5ﾊ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
Copyrightｩ The Japanese Pharmacological Society 2000
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