大鼠心室肌细胞调节性细胞容积减小的离子通道机制
Ion channel mechanism of regulatory volume decrease in rat ventricular myocytes
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摘要: 目的 观察成年大鼠心室肌细胞调节性细胞容积减小（regulatory volume decrease，RVD）的过程，探讨参与RVD过程的离子通道机制。方法 将急性分离的大鼠心室肌细胞放入低渗溶液中,利用细胞体积测量系统测定细胞平均容积的变化过程和离子通道的参与过程。结果 大鼠心室肌细胞具有良好的RVD功能;该过程可被氯通道阻断剂如蒽-9-羧酸(anthracene-9-carboxylic acid,9-AC，500 μmol/L)和钾通道阻断剂CsCl(5 mmol/L)所阻断。进一步的研究发现,ATP敏感钾通道(KATP)的阻断剂格列苯脲(glibenclamide,10 μmol/L)可以明显地抑制细胞的RVD过程。结论 成年大鼠心室肌细胞具有RVD功能，RVD过程的完成有赖于氯通道和钾通道的平行激活,ATP敏感钾通道是参与容积调节的钾通道之一。Abstract: AIM: To observe the regulatory volume decrease (RVD) process of rat ventricular myocytes and to investigate its ion channel mechanism. METHODS: Isolated rat ventricular myocytes were exposed to hypotonic solution and the cell volume was measured using Coulter Counter System. RESULTS: Rat ventricular myocytes showed a RVD process and this process was blocked by Cl- channel blocker 9-AC and K+ channel blocker CsCl. Further results demonstrated that a subtype of the K+ channel involved in RVD was an ATP-sensitive K+ channel because of its high sensitivity to glibenclamide. CONCLUSION: The RVD process of rat ventricular myocytes is dependent on the parallel activation of Cl- channel and K+ channel. The subtype of K+ channel involved in the RVD process is ATP-sensitive K+ channel.
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