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. METHORDS ①Vasoconstriction experiments with aorta strips of rats. ② In vivo experimentsmale 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.②The compound(30 mg?kg -1 .iv) markedly antagonized ET 1 induced the long lasting pressor phase mediated by ET A without affecting early transient depressor phase by ET B. CONCLUSION iQWcF is one of ET A selective antagonists.