硫化氢对离体豚鼠乳头状肌的电生理效应  

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

作　　者：许萌[1] 武宇明[1] 李茜[1] 王福伟[1] 何瑞荣[1] 

机构地区：[1]河北医科大学基础医学研究所生理室,石家庄050017

出　　处：《生理学报》2007年第2期215-220,共6页Acta Physiologica Sinica

基　　金：This work was supported by the National Science Foundation of Hebei Province (No. C200700821).

摘　　要：应用细胞内微电极技术,观察硫化氢(hydrogen sulfide,H2S)对离体豚鼠乳头状肌细胞的电生理效应。结果表明:(1)NaHS (H,S的供体,50、100、200μmol/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 (100μmol／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+,KATP)通道阻断剂格列苯脲(glibenclamide,Gli,20μmol／L),可部分阻断NaHS(100μmol／L)的电生理效应。(4)预先应用L型钙通道开放剂Bay K8644(0．5μmol／L),可部分阻断NaHS(100μmol／L)的电生理效应。(5)预先应用含Gli(20μmol／L)的无钙Krebs-Henseleit液灌流标本,可完全阻断NaHS(100μmol／L)的电生理效应。(6)DL-propargylglycine(PPG,一种胱硫醚-γ-裂解酶的不可逆抑制剂,200μmol／L)可延长正常乳头状肌的动作电位时程。以上结果提示,H,S可能通过兴奋KATP通道促进K+外流,同时抑制Ca2+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H2S可能发挥重要的电生理作用。The cardiac electrophysiological effects of hydrogen sulfide （H2S） 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 NariS （H2S donor, 50, 100, 200 ~nnol/L） in a concentration-dependent manner; （2） in partially depolarized papillary muscles, 100 μmol/L NariS not only reduced APD, but also decreased the amplitude of action potential （APA）, overshoot （OS） and maximal velocity of depolarization at phase 0 （Vmax）; （3） pretreatment with ATP-sensitive K^＋ （KATP） channel blocker glibenclamide （20 μmol/L） partially blocked the effects of Naris （100 μmol/L）; （4） pretreatment with L-type Ca^2＋ channel agonist Bay K8644 （0.5 μmol/L） also partially blocked the effects of NariS （100 μmol/L）; （5） pretreatment with Ca^2＋-free KrebsHenseleit solution containing glibenclamide （20 μmol/L） completely blocked the effects of Naris （100 μmol/L）; （6） APD in the normal papillary muscles was increased by DL-propargylglycine （PPG, an inhibitor of cystathionine y-lyase, 200 μmol/L）. All these results suggest that the electrophysiological effects of H2S on papillary muscles in our study are due to an increase in potassium efflux through the opening of KATP channels and a decrease in calcium influx. Endogenous H2S may act as an important regulator in electrophysiological characters in papillary muscles.

关 键 词：电生理 硫化氢 动作电位 乳头状肌 

分 类 号：Q445[生物学—生理学]