Effects of angiotensin I of the american bullfrog Rana catesbeiana on amphibian tissues

Abstract

1. 1. The effect of bullfrog angiotensin I [Asp 1, Val 5, Asn 9] angiotensin I, (AT I) on short-circuit current (SCC) on isolated toad skin and aorta contractility was examined. 2. 2. AT I increased SCC in toad skin, the effect was partially inhibited by angiotensin-converting enzyme inhibitor (ACEI) teprotide. 3. 3. AT I induced contractile responses in isolated rings of toad aorta. This effect was partially inhibited by captopril and completely blocked by the peptide antagonist [Sar 1, Ile 8] angiotensin II. 4. 4. Present results indicate that this homologue AT I would act in amphibian tissues by conversion to AT II.