氟灭酸对豚鼠微动脉平滑肌细胞BKCa通道的增强作用

Flufenamic acid enhances BKCa channel of vascular smooth muscle cells of arterioles in guinea pig

目的观察氟灭酸对微动脉平滑肌细胞电生理学特性的影响。方法应用全细胞膜片钳技术在离体豚鼠脑动脉(BA)和肠系膜动脉(MA)的平滑肌细胞上,观察氟灭酸(100~1 000μmol/L)对微动脉平滑肌细胞膜电流的影响。结果 4-氨基吡啶(1 mmol/L)和四乙胺(1 mmol/L)都可以部分抑制微动脉平滑肌细胞膜电流。氟灭酸可以浓度依赖的增强微动脉平滑肌细胞膜电流,100、300和1 000μmol/L氟灭酸分别使BA平滑肌细胞膜电流幅度(+40 mV)增强了(36±14)%、(136±26)%和(223±24)%,使MA平滑肌细胞膜电流幅度(+40mV)分别增强了(45±11)%、(166±24)%和(278±24)%。氟灭酸增强平滑肌细胞膜电流具有电压依赖性,氟灭酸主要增强0^+40 mV电压区间的激活电流,其中对+40 mV激活电流的增强作用最强。背景灌流四乙胺(1mmol/L)能显著抑制氟灭酸对微动脉平滑肌细胞膜电流的增强作用。结论氟灭酸可以浓度和电压依赖的激活微动脉平滑肌细胞膜上BKCa通道。

To investigate the effects of flufenamic acid（FFA） on the membrane electrophysiological properties of vascular smooth muscle cells（VSMCs） in arterioles.【Methods】Whole-cell patch clamp recording technique was used to investigate the effects of 100 ～1 000 μmol/L FFA on the membrane current of VSMCs in guinea pig brain artery（BA） and mesenteric artery（MA）.【Results】1 mmol/L 4-AP and 1 mmol/L TEA both could partially inhibit the whole-cell membrane current of dissociated VSMCs in arterioles.FFA enhanced the membrane current of VSMCs in a concentration-dependent manner.The enhanced rates of FFA（100,300 and 1000 μmol/L） on the membrane current of VSMCs（＋40 mV） were（36±14%）,（136±26%） and（223±24%） in BA respectively,and（45± 11%）,（166±24%） and（278±24%） in MA.FFA also enhanced the membrane current of VSMCs in a voltage-dependent way.FFA induced a more pronounced enhancement of the membrane current from 0 to ＋40 mV,especially at ＋ 40 mV.In the presence of 1 mmol/L TEA,the effect of FFA on the membrane current of VSMCs was significantly inhibited.【Conclusion】FFA enhances BKCa channel of VSMCs of arterioles in guinea pig by concentration and voltage-dependent way.