Effects of SK&F 82526 and SK&F 83742 on the renal vascular dopamine receptor

Abstract

The renal vascular effects of benzazepine derivatives were studied on the isolated perfused rat kidney in the presence of phenoxybenzamine and sotalol after contraction of the vascular bed with prostaglandin F2 alpha. SK&F 82526 was a very potent dopaminomimetic drug (ED50 = 7.6 +/- 0.8 X 10(-9) M) on the renal vascular dopamine receptor. It displayed partial agonist activity (similar to SK&F 38393) and was devoid of alpha-adrenomimetic effects. SK&F 83742 was a potent dopaminolytic drug. It antagonized dopamine-induced relaxation of the renal vascular bed in a competitive way, with an apparent pA2 of 7.47 +/- 0.23.