大鼠心室肌细胞牵张活化电流I_(cir,swell)的研究  

The study of swelling - activated inward rectifier cation currents I_(Cir,swell) in rats ventricular myocytes

作　　者：李晓峰[1] 马爱群[2] 

机构地区：[1]石河子大学医学院第一附属医院,832008 [2]西安交通大学第一医院内科,710061

出　　处：《农垦医学》2003年第5期313-315,共3页Journal of Nongken Medicine

摘　　要：目的:探讨大鼠心室肌细胞肿胀激活内向整流阳离子流I_(Cir,swell)与低渗性肿胀时体积的关系及对牵张活化离子通道阻断剂Gd^(3+)的敏感性。方法:①采用图文采集及分析系统测量并比较大鼠心室肌细胞在等渗(1T)及低渗(0.6T)溶液中体积的变化。②采用全细胞电压钳方式记录大鼠心室肌细胞在1T及0.6T溶液中I_(Cir,swell)的变化。结果:①大鼠心室肌细胞在0.6T溶液中比1T溶液中体积分别增加37.4％和35.9％。②正常细胞在1T溶液中未见电流激活,在0.6T溶液中的细胞肿胀使内向及外向电流同时增大,其内向电流在-100mV电压刺激时的电流强度由1T溶液的-1.55±0.23pA/pF增大至0.6T溶液中的-6.45±1.03pA/pF(P<0.01),并能被10μM Gd^(3+)抑制。结论:心肌细胞低渗性肿胀可激活牵张活化电流I_(Cir,swell),且可被Gd^(3+)抑制,I_(Cir,swell)可能在机械-电反馈导致心律失常的过程中起重要作用。objective: To explore the changes of swelling- activated ion currents ICir,swell in mechanoelectric conduction. Methods:①The image acquiring and analysis system was used to determine the changes of the volume of the rats myocytes in iso-tonic and hypotonic solution. ②The currents elicited by swelling in solution with 0.6× normal osmolarity ,namely ICir,swell, were studied using patch clamp techniques with whole- cell voltage clamp configuration. Resultes:①The volume of the ventricular my-ocytes increased in 0,6T media by 37 .4% and 35 .9% , respectively. ②Cell swelling in 0.6T solution caused activation of an large inwardly rectifying at negative potentials increased in amplitude, at -100mV from - 1.55±0 .23pA/pF to - 6.45±1 .03pA/pF (P<0.01) which was blocked by 10μM Gd3+ . Conclusion: ① Osmotic cell swelling of rat ventricular myocytes activated cation stretch/swelling activated channels-ICir,swell, which could be blocked Cd3 + .② The stretch - activated ICir,swell may take an important role in stretch induced arrhythmia.

关 键 词：大鼠 心室肌细胞 牵张活化电流Icir swell 膜片钳技术 牵张活化离子通道 机械电反馈 

分 类 号：R337.5[医药卫生—人体生理学]