摘要
目的:揭示氧自由基导致跨膜电位变化的离子电流基础。方法:采用全细胞膜片钳技术,观察了H2O2(1mmol/L)对豚鼠单个心室肌细胞不同钾通道的影响。结果:H2O2使豚鼠心肌细胞静息电位(RP)降低,动作电位时程(APD)显著缩短的同时,明显抑制超极化时的内向整流钾电流(Ik1),致(Ik1)正常呈N字型I-V曲线几乎变成一条斜线;增强延迟整流钾电流(IK)的快组分(IKr)和侵组分(IKs),尤其IKr增加更显著,并使电流电压曲线向右上偏移。结论:氧自由基对心室肌细胞的IK1和IK的不同影响,是其所致跨膜电位变化和心律失常的可能离子机制。
AIM: To reveal ionic curret basis of the change of transmembrane potential induced by oxygen free radical.METHOD:The wholfe cell mecording pach clamp techique was used to investigate the effect of H2O2(1 mmol/ L) on differen potassium channel ionic currents of ventricular myocytes of guinea pig. RESULTS : It was found that H2O2 reduced rest potential (RP) and shortened action potential duration (MPD) significantly , inhibited the inward rectifier K current(IK1)markedly ,H2O2 changed the current - voltage (I- V) relation to IK1 from a N shape to a /shape and enhaned the rapid component (IKr) and the slow compoent (IKs) of the delayed outward retifier K current (Ik), especially Ikr, and made IK I - V curve shift to up - right. CONCLUSION: Different effects of oxygen free radical on IK1 and IK of ventricular myocytes is a possible ionic mechanism for the chang of transmembrane potential and arrhythmia indued by oxygen free redical.
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
1999年第9期773-776,共4页
Chinese Journal of Pathophysiology
基金
国家自然科学基金!39570305
关键词
心律失常
钾离子通道
动作电位
氧自由基
Hydrogen peroxide
Guinea pigs
Myocardium
Ion channels
Arrhythmia