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安定对兔心乳头肌动作电位和收缩的作用

韩新强, 汤树本, 张海燕

河南医科大学生理学教研室. 河南

摘要

该文观察了安定、戊脉安和PK11195对兔心乳头肌动作电位和收缩的作用,并比较了安定对兔与豚鼠心肌收缩作用的差异。安定[0.7×10~(-6)-22.4×10~(-6)mol/L]使兔乙乳头肌动作电位时程(APD)及钙依赖动作电位(Ca-AP)时程缩短,并使Ca-AP的最大上升速率[V_(max)]和幅值减小;安定还抑制兔与豚鼠心室乳头肌的收缩,相比之下对豚鼠的作用更明显。在戊脉安[2×10~(-6)mol/L]作用下,兔心乳头肌Ga-AP逐渐消失。提高溶液中Ca~(2+)的浓度可拮抗安定和戊脉安的作用。

关键词： 兔心乳头肌; 苯二氮(艹卓)受体; 安定; PK11195

Effects of diazepam on the action potential and contractility of rabbit papillary muscle

Han Xinqiang, Tang Shuben, Zhang Haiyan

Department of Physiology, Henan Medical University. Zhengzhou, China

Abstract

Effects of diazepam, verapamil and PK11195 on the action potential and contractility of the rabbit papillary muscle were investigated. Some comparisons were also made between the effects of diazepam on the contractility of the rabbit and the guinea pig. 0.7-22.4×10~(-6)mol/L diazapem shortened the duration of the action potential,(APD) and calcium-dependent action potential (Ca-AP), and decreased the maximum rise rate as well as the amplitude of the Ca-AP in the rabbit papillary muscle, which was accompanied by a decrease of contractility. The effect of diazepam on the contractility was more pronounced in the guinea pig. 2×10~(-6)mol/L verapamil suppressed the Ca-AP of the rabbit papillary muscle, an effect that.could be antagonized by increasing the external calcium concentration. The curve relating APD or contractility to diazepam dosage could be shifted to the right by 1×10~(-6) mol/L PKI 1195. In the presence of PK11195, the Ca-AP was.more resistant to the effect of verapamil. Our experimental results suggest: (a) Benzodiazepine binding sites in the rabbit papillary muscle may act as peripheral benzodiazepine receptors; (b) Activation of these receptors can result in a decrease of calcium influx; (c) Species differences may exist in the density and responsibility of this receptor.

Key words: Rabbit papillary muscle;Benzodiazepine receptor;Dizzepam;PK11195

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引用本文：

韩新强, 汤树本, 张海燕. 安定对兔心乳头肌动作电位和收缩的作用[J]. 生理学报 1987; 39 (4): .

Han Xinqiang, Tang Shuben, Zhang Haiyan. Effects of diazepam on the action potential and contractility of rabbit papillary muscle. Acta Physiol Sin 1987; 39 (4): (in Chinese with English abstract).