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内皮素对豚鼠乳头肌电生理和收缩活动的影响

张朝, 李玉龙, 何瑞荣

河北医科大学基础医学研究所生理室.河北,石家庄 050017

摘要

应用细胞内微电极和肌张力记录技术,观察了ET-1对豚鼠乳头肌细胞电生理和机械收缩活动的影响。结果表明：ET-1浓度依赖地明显延长PPD和APD_(90),增加心肌收缩张力;钾通道阻断剂TEA不影响ET-1的生物效应;而L型钙通道阻断剂硝苯吡啶、ET_(A)受体选择性拮抗剂BQ-123和APⅢ以浓度依赖的方式阻断ET-1的上述效应,提示ET-1对乳头肌的电生理和正性肌力效应是由ET_(A)受体亚型介导的,与胞浆内Ca~(2+)升高有关。

关键词： 内皮素; TEA; BQ－123; 硝苯吡啶; APⅢ; 乳头肌; 电生理

Effects of endothelin on electrophysiological and contractile activity of guinea pig papillary muscles

Zhang Zhao, Li Yulong, He Ruirong

Department of Physiology, Institute of Basic Medicine, Hebei Medical University. Shijiazhuang 050017, Hebei

Abstract

Effects of endothelin on electrophysiological activity and contractility were examined in guinea pig papillary muscle using intracellular microelectrode and contractile tension recording technique. The results indicated that ET-1 prolonged APD, especially PPD and increased the contractile tension in a dose-dependent manner. The ET-induced effects were not influenced by K~(+) channel blocker TE_(A), but inhibited by L-type CA~(2+) channel blocker nifedipine, ET_(A) receptor selective antagonist BQ-123 and atriopeptin Ⅲ in a concentration-dependent manner. It is suggested that the changes in electrophysiological activity and the positive inotropic effect induced by ET-1 in guinea pig muscles are due to the elevation of intracellular calcium, which may be mediated by ET_(A) receptor.

Key words: Endothelin;BQ-123;TEA;Nifedipine;AtriopeptinⅢ;Pepillary muscle;Electrophysiology

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引用本文：

张朝, 李玉龙, 何瑞荣. 内皮素对豚鼠乳头肌电生理和收缩活动的影响[J]. 生理学报 1997; 49 (2): .

Zhang Zhao, Li Yulong, He Ruirong. Effects of endothelin on electrophysiological and contractile activity of guinea pig papillary muscles. Acta Physiol Sin 1997; 49 (2): (in Chinese with English abstract).