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硫化氢对离体豚鼠乳头状肌的电生理效应

许萌, 武宇明, 李茜, 王福伟, 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

应用细胞内微电极技术,观察硫化氢(hydrogen sulfide,H_(2)S)对离体豚鼠乳头状肌细胞的电生理效应。结果表明:(1)NaHS (H_(2)S的供体,50、100、200#mu#mol/L)可浓度依赖地缩短正常乳头状肌的动作电位时程。(2)对部分去极化乳头状肌,NaHS (100#mu#mol／L)除缩短动作电位时程外,还降低动作电位幅值和超射值,减慢零相最大上升速度。(3)预先应用ATP敏感性钾(ATP--sensitive K~(+),K_(ATP))通道阻断剂格列苯脲(glibenclamide,Gli,20#mu#mol／L),可部分阻断NaHS(100#mu#mol／L)的电生理效应。(4)预先应用L型钙通道开放剂Bay K8644(0.5#mu#mol／L),可部分阻断NaHS(100#mu#mol／L)的电生理效应。(5)预先应用含Gli(20#mu#mol／L)的无钙Krebs--Henseleit液灌流标本,可完全阻断NaHS(100#mu#mol／L)的电生理效应。(6)DL--propargylglycine(PPG,一种胱硫醚--#gamma#--裂解酶的不可逆抑制剂,200#mu#mol／L)可延长正常乳头状肌的动作电位时程。以上结果提示,H_(2)S可能通过兴奋K_(ATP)通道促进K~(+)外流,同时抑制Ca~(2+)内流,进而影响豚鼠乳头状肌电生理效应。乳头状肌中内源性H_(2)S可能发挥重要的电生理作用。

关键词： 电生理; 硫化氢; 动作电位; 乳头状肌

Electrophysiological effects of hydrogen sulfide on guinea pig papillary muscles {sl in vitro}

Xu Meng, Wu Yuming, Li Qian, Wang Fuwei, He Ruirong

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

Abstract

The cardiac electrophysiological effects of hydrogen sulfide (H_(2)S) were examined in guinea pig papillary muscles in vitro using intracellular microelectrode technique. The results obtained were as follows: (1) the duration of action potential (APD) in the normal papillary muscles was decreased by NaHS (H_(2)S donor, 50, 100, 200 #mu#mol/L) in a concentration-dependent manner; (2) in partially depolarized papillary muscles, 100 #mu#mol/L NaHS not only reduced APD, but also decreased the amplitude of action potential (APA), overshoot (OS) and maximal velocity of depolarization at phase 0 (V_(max)); (3) pretreatment with ATP-sensitive K~(+) (K_(ATP)) channel blocker glibenclamide (20 #mu#mol/L) partially blocked the effects of NaHS (100 #mu#mol/L); (4) pretreatment with L-type Ca~(2+) channel agonist Bay K8644 (0.5 #mu#mol/L) also partially blocked the effects of NaHS (100 #mu#mol/L); (5) pretreatment with Ca~(2+)-free KrebsHenseleit solution containing glibenclamide (20 #mu#mol/L) completely blocked the effects of NaHS (100 #mu#mol/L); (6) APD in the normal papillary muscles was increased by DL-propargylglycine (PPG, an inhibitor of cystathionine #gamma#-lyase, 200 #mu#mol/L). All these results suggest that the electrophysiological effects of H_(2)S on papillary muscles in our study are due to an increase in potassium efflux through the opening of K_(ATP) channels and a decrease in calcium influx. Endogenous H_(2)S may act as an important regulator in electrophysiological characters in papillary muscles.

Key words: electrophysiological;hydrogen sulfide;Action potential;papilary muscles

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引用本文：

许萌, 武宇明, 李茜, 王福伟, 何瑞荣. 硫化氢对离体豚鼠乳头状肌的电生理效应[J]. 生理学报 2007; 59 (2): 215-220.

Xu Meng, Wu Yuming, Li Qian, Wang Fuwei, He Ruirong. Electrophysiological effects of hydrogen sulfide on guinea pig papillary muscles {sl in vitro}. Acta Physiol Sin 2007; 59 (2): 215-220 (in Chinese with English abstract).