α-Adrenoceptor blocking action of hymenin, a novel marine alkaloid

Abstract
In the rabbit isolated aorta, hymenin (10−6 M) a novel marine alkaloid, caused a parallel rightward shift of the dose-response curve for norepinephrine without affecting that for histamine or KCl, suggesting that hymenin is a competitive antagonist of α-adrenoceptors in vascular smooth muscles.