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目的： 探讨慢性缺氧及川芎嗪长期应用对豚鼠右室心肌细胞钾电流的影响。方法：采用全细胞膜片钳技术分别记录并比较正常对照组、缺氧组、药物（ 川芎嗪） 治疗组豚鼠单个右室心肌细胞的膜电容、延迟整流钾电流峰值和电流－ 电压关系曲线及内向整流钾电流－ 电压关系曲线。结果：上述３ 组细胞膜电容分别为（１５４ ．９ ±１６ ．７） ｐＦ、（１７７ ．３ ±１４ ．３）ｐＦ、（１６０ ．５ ±１３ ．９）ｐＦ，其中缺氧组显著大于另两组（ Ｐ＜ ０－０１） ；延迟整流钾电流峰值分别为（１ ．１３ ±０ ．２９）ｎＡ、（０ ．７９ ±０ ．２１） ｎＡ、（１ ．０３ ±０ ．２３） ｎＡ，其中缺氧组显著低于另两组（ Ｐ＜ ０－０５） ；在－ ２０ ｍ Ｖ～＋ ６０ ｍ Ｖ，慢性缺氧组延迟整流钾电流密度较另两组显著下降（ Ｐ＜ ０－０５） 。３ 组之间的内向整流钾电流无显著差异（ Ｐ＞ ０－０５） 。结论： 慢性缺氧不改变豚鼠右室心肌细胞内向整流钾电流，但能使细胞膜电容增加，延迟整流钾电流幅度和电流密度下降；长期应用川芎嗪能在一定程度上减轻这些变化
Objective: To investigate the effects of chronic hypoxia and long-term use of tetramethylpyrazine on potassium currents in right ventricular myocytes of guinea pigs. Methods: The whole-cell patch clamp technique was used to record and compare the membrane capacitance, peak value of delayed rectifier potassium current, current-voltage curve and inward direction of single right ventricular cardiomyocytes of normal control group, hypoxia group and drug (tetramethylpyrazine) treatment group. Rectifier potassium current - voltage curve. RESULTS: The membrane capacitances of the three groups were (154.9 ± 16.7) pF, (177.33 ± 14.3) pF, and (160.5 ± 13.9) pF, respectively. The hypoxia group was significantly greater than the other two groups. Group (P <0-01); delayed rectifier potassium current peaks were (1 .13 ± 0 .29) nA, (0.79 ± 0 .21) nA, (1 .03 ± 0 .23) nA, respectively. Hypoxia was significantly lower in the hypoxic group than in the other two groups (P < 0-05). Delayed rectifier potassium current density in the chronic hypoxia group was significantly lower at -20 m V to + 60 m V than in the other two groups (P < 0-05). . There was no significant difference in inward rectifier potassium currents among the 3 groups (P > 0-05). Conclusion: Chronic hypoxia does not change the inward rectifier potassium current in right ventricular myocytes of guinea pigs, but it can increase the membrane capacitance, delay the amplitude of rectifier potassium current and decrease the current density. Long-term application of tetramethylpyrazine can alleviate these changes to some extent.