大鼠心房肌细胞三磷酸腺苷敏感钾通道的牵张敏感性

Mechanosensitivity of ATP-sensitive potassium channels in rat atrial myocytes

目的研究成年大鼠心房肌细胞三磷酸腺苷敏感钾通道(KATP)的牵张敏感性。方法应用单通道膜片钳技术在开放细胞贴附模式下记录大鼠心房肌细胞上KATP通道的电活动,并研究KATP通道对机械刺激的反应。结果根据通道的激活方式、药理学特性、I-V曲线、反转电位及整流特性,确定所记录的通道为KATP通道。进一步研究表明该通道的开放概率对负压刺激呈现强度依赖性。结论大鼠心房肌细胞上的KATP通道对牵张刺激敏感。

Objective To study the mechanosensitivity of KATP channel in rat atrial myocytes. Methods KATP channel activity was recorded in open cell-attached mode with patch-clamp techniques and its stretch-sensitivity was characterized. Results KATP channels recorded in atrial myocytes were confirmed on the basis of activating manner, pharmacological properties, I-V curve, reversal potential and rectification property. Further experiments proved that the open probability of KATP channel increased in a pressure-dependent pattern. Conclusion The KATP channel in atrial myocytes is sensitive to stretch stimuli.