Action of dauricine on aortic strips
Chen, S.H.; Hu, C.J.
Zhongguo Yao Li Xue Bao 3(3): 178-182
1982
ISSN/ISBN: 0253-9756 PMID: 6216727 Document Number: 195263
Dauricine (Dau) inhibited both contractions evoked by Adr [adrenaline, epinephrine] or high K+ in rabbit thoracic aortic strips and those caused by NA [noradrenaline, norepinephrine] in normal or hypertensive rat aortic strips. Dau shifted the dose-response curves for NA, KCl and CaCl2 to the right and depressed their maximal responses. Dau produced neither .alpha.-adrenoceptor-blocking nor .beta.-adrenoceptor-stimulating effects. Dau antagonized Na and Ca2+ in a noncompetitive manner. The antagonism of Dau against NA was a potent as that of verapamil (Ver), but it was much weaker than Ver against Ca2+. Dau inhibited both the fast and transitory contraction .**GRAPHIC**. responses evoked by Na in Ca2+-free medium and the slow sustained contraction .**GRAPHIC**. response after the supplement of CaCl2. Ver inhibited the fast and transitory contraction response, but not the slow sustained contraction response. The Dau-induced relaxation on vascular smooth muscle might result from its antagonistic effect to Ca2+, and the mode of this antagonism differed from that of Ver. These 2 drugs may interfere with 2 different transmembrane Ca2+ channels.