细胞外液酸碱度对主动脉平滑肌细胞电生理的影响

目的 :探讨细胞外液酸碱度 ( p H0 )的改变对主动脉平滑肌细胞电生理特性的影响。方法 :通过改变培养的乳鼠主动脉平滑肌细胞外液的酸碱度 ,应用全细胞膜片钳技术记录细胞膜的变化和钾离子通道活动的情况。结果 :p H0 降低时引起细胞膜超极化 ,外向钾电流增大 ;反之 ,p H0升高时引起细胞膜去极化 ,外向钾电流减小。这种变化可以被 TEA阻断 ,而对 4- AP不敏感。结论 :p H0 改变引起主动脉平滑肌细胞膜电位及外向电流幅值变化 ,其机制可能与钙激活性钾通道的开放几率有关

Effects of pH0 on Electrophysiological Activities of Aortic Smooth Muscle Cells

Objective: To study on the pH 0 effects of changes on membrane potential and K + channels activity in aortic smooth muscle cells. Methods: The extracellular fluid pH 0 of cultivated aortic smooth cells was changed, then the membrane potential and K + currents were recorded with whole cell patch clamp technique. Results: The membrane potential hyperpolarized and outward K + currents increased with the decreasing pH 0. On the contrary, the membrane potential depolarized and outward K + currents decreased with the elevating pH 0 and the changes could be blocked by TEA but not by 4 AP. Conclusion:The changes of membrane potential and K + channels in aortic smooth muscle cells induced by pH 0 may be connected with the open activity of the Ca activated K + channels.