タイトル無し

概要

論文の詳細を見る
Effects of some α- and β-adrenoceptor agonists were investigated on the isolated rabbit sphincter of Oddi and duodenum. 1. In both preparations, noradrenaline (10-6-10-5M) inhibited the rhythmic spontaneous contractions, and the inhibition was observed more markedly in the sphincter than in the duodenum. 2. In the duodenum, phenylephrine (10-6-10-5M) induced an inhibition of the contractions of rapid onset followed by an increase in contraction height. The response resembled that by noradrenaline in the presence of propranolol 10-6M. 10-5M of phenylephrine introduced the increase in contractions more remarkably than 10-6 M of the drug. Isoproterenol (10-7-10-6M), as well as noradrenaline in the presence of phentolamine 10-5M, proudced an inhibition of slow onset which was maintained throughout the presence of the drug. The inhibition by noradrenaline with phentolamine was more intense than that without phentolamine. Qualitatively similar responses to phenylephrine and isoproterenol were observed on the sphincter of Oddi. 3. In both preparations, tetrodotoxin at 10-7M potentiated the inhibition induced by noradrenaline, depressed the increase in contractions by phenylephrine, but hardly affected the response to isoproterenol. 4. The results indicate that, in the sphincter of Oddi and duodenum in rabbits, adrenergic agonists produce inhibition of the contractions via α- and β-receptors in the smooth muscle fibres, and abrupt inhibition by α-agonist may cause excitatory response mediated through neural consequence.
日本平滑筋学会の論文

タイトル無し

スポンサーリンク

概要

著者

関連論文

スポンサーリンク