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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。
OBJECTIVE: To reveal the ion current basis for the change of transmembrane potential induced by oxygen free radicals. Methods: The whole cell patch clamp technique was used to observe the effect of H2O2 (1 mmol / L) on different potassium channels in single ventricular myocytes of guinea pigs. Results: The resting potential (RP) of cardiomyocytes in guinea pigs was decreased and the potential duration of action potential (APD) was significantly shortened by H2O2. At the same time, the inward rectifier potassium current (Ik1) (IKr) and intrusion components (IKs) of the delayed rectified potassium current (IK). In particular, the IKr increases more significantly and shifts the current-voltage curve to the upper right . Conclusion: The different effects of oxygen free radicals on IK1 and IK in ventricular myocytes are possible ion mechanisms of transmembrane potential changes and arrhythmia.