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200~250g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:①pH。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-+60mV区间的电流幅度;②1mmol/LTEA可以有效抑制pH。酸化对脑动脉平滑肌细胞外向电流的抑制作用。结论:pH0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.