The antagonizing activity of a novel peptide analogs, iQWcF, on the function of endothelin receptors / 中国药理学通报

ABSTRACT

AIM: To evaluate the antagonizing activity of iQWcF, a modified tripeptide, to endothelin receptors. METHODS: 1 Vasoconstriction experiments with aorta strips of rats. 2 In vivo experiments male normotensive Wistar rats were anesthetized with pentobarbital-Na (50 mg·kg-1), and catheterized into the carotic artery for measurement of blood pressure, and into the femoral vein for administration of iQWcF (30 mg·kg-1) and ET-1(0.9 nmol ·kg-1). The test compound was given intravenously 5 min before the bolus injection of ET-1. Control animals received saline on the same time schedule. The blood pressure was recorded at different time interval after injecting ET-1. RESULTS: 1iQWcF prohibited the vascontriction of aorta induced by ET-1 in a concentration-dependent fashion. 2 The compound (30 mg·kg-1. iv) markedly antagonized ET-1-induced the long-lasting pressor phase mediated by ETA without affecting early transient depressor phase by ETB. CONCLUSION: iQWcF is one of ETA-selective antagonists.