Effect of Cyclovirobuxine D(CVB-D) on Oddi's sphincter contraction / 中成药

ABSTRACT

AIM: To study the effect of CVB-D on contraction of guinea pig Oddi's sphincter in vitro. METHODS: Within the range from 1?10 -7 M to 3?10 -6 M, CVB-D's effects on the smooth muscle under the following conditions were observed 1) the two phases of the Oddi's sphincter contractive curve caused by 80 mM K+ and 5?10 -6 M Ach; 2)together with verapamil, the contraction of Oddi's sphincter induced by 80 mM K+ and 5?10 -6 M Ach respectively. RESULTS: The relation between the amount of CVB-D and rapid contraction of desived inihibitory response was possessed of a dose-effect one, as well as ratio of plateau and peak of contractions, and slightly elevated contraction in continuous phase. CVB-D kept rapid phase peak value and plateau/peak value decreased markedly that expressed a dose-effect relationship. Contrary to CVB-D. Ach caused rapid, continuous phase and plateau/peak value to fall according as CVB-D decreased. Combination of verapamin and CVB-D led rapid phase peak value induced by KCl to lessen, but do not influence verapamin plateau used only and vanish plateau of rapid phase induced by Ach. CONCLUSION: CVB-D's effects on the contraction of Oddi's sphincter are related to the agonists and contractive phases, which reflect its effects on Ca 2+ channels.