Open AccessContractile Responses Of Isolated Dog Mesenteric Arteries to Angiotensin I, II and III
Author(s) -
Noboru Toda,
Shigehiro Hayashi,
Mizuo Miyazaki
Publication year - 1978
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.28.527
Subject(s) - tachyphylaxis , medicine , angiotensin ii , endocrinology , phentolamine , saralasin , contraction (grammar) , methysergide , mesenteric arteries , chemistry , bradykinin , angiotensin iii , renin–angiotensin system , receptor , angiotensin ii receptor type 1 , antagonist , artery , blood pressure
The addition of angiotensin (Ang-) I, II and III caused a dose-dependent contraction of helically cut strips of dog mesenteric arteries. Tachyphylaxis developed following repeated additions of angiotensins. Average median effective concentrations of Ang-I, II and III were 3.7, 0.8 and 2.5 X 10(-8) M, respectively. Contractile responses to the angiotensins were attenuated to a similar extent by Ang-II antagonists, Sar1 Ileu8 Ang-II and Sar1 Ala8 Ang-II, but were unaffected by phentolamine, methysergide and diphenhydramine. The response to Ang-I was significantly reduced by treatment with bradykinin-potentiator B, while the response to Ang-II was not influenced. It may be concluded that Ang-I, II and III produce contractions possibly by activation of same Ang-II receptors and that contractions induced by Ang-I are associated, to some extent, with a conversion to Ang-II in the arterial wall.