细胞外液酸碱度改变对自发性高血压大鼠脑动脉平滑肌细胞电生理特性的影响

The effects of pHo on electrophysiological properties of VSMCs in brain artery of spontaneously hypertensive rats

目的:探讨细胞外液酸碱度(pHo)的改变对自发性高血压大鼠(SHR)脑动脉平滑肌细胞电生理特性的影响。方法:取200~250 g自发性高血压大鼠,应用全细胞膜片钳记录技术观察细胞外液酸碱度改变后对SHR脑动脉平滑肌细胞膜电流的作用,进一步揭示其离子机制。结果:①pHo酸化可电压依赖性的抑制SHR脑动脉平滑肌细胞的外向电流。其主要抑制SHR脑动脉平滑肌细胞0^+60 mV区间的电流幅度;②1 mmol/L TEA可以有效抑制pHo酸化对脑动脉平滑肌细胞外向电流的抑制作用。结论:pHo的改变引起SHR脑动脉平滑肌细胞外向电流变化,其可能与电压依赖性的抑制SHR脑动脉平滑肌细胞BKCa通道电流有关。

Objective： To investigate the effects of pHo on the electrophysiological properties of vascular smooth muscle cells （VSMCs） in brain artery of spontaneously hypertension rats （SHR）. Methods： We studide the effects and the ion mechanism of pHo on whole-cell mem- brane current of VSMCs in brain artery of 200 - 250 g SHR by whole-cell patch clamp recordings. Results： OAcidic pHo could inhibit the outward current of VSMCs of brain artery in SHR in a voltage-depedent mariner. It induced a more pronounced inhibition of the outward current from 0 to ＋ 60mV; （2） In the presence of 1 mmol/L TEA, the inhibition of acidic pHo on the outward current of VSMCs of brain artery was in- hibited. Conclusion： The changes of outward current of VSMCs of brain artery in SHR induced by pHo may be connected with BKCa channel.