3、4-二羟基苯乙酮对大鼠肺内动脉平滑肌细胞钾电流的影响

目的　研究 3、4 二羟基苯乙酮 (3、4 Dihydroxyace tophenone,DHAP)对钾通道的作用。 方法　建立大鼠肺内动脉平滑肌全细胞膜片钳方法并观察 3、4 二羟基苯乙酮对大鼠肺内动脉平滑肌细胞钾离子通道的作用。结果　①将平滑肌细胞钳制在 - 4 0mV ,给予从 - 30mV复极化至 +6 0mV、阶跃电压为 10mV、脉冲时间是 30 0ms的去极化刺激10次时 ,可记录到时间及电压依赖性的延迟整流钾电流。②在指令电位 +5 0mV、+6 0mV时 ,细胞外给予 10 -6mol·L-1DHAP 5min后 ,可使该电流由用药前 (12 97± 2 4 5 )、(16 83± 3 2 8)pA/pF ,增加至 (18 2 9± 2 6 3)、(2 2 90±3 2 1)pA/pF ,增加百分比为 4 1%和 36 % (P <0 0 5 ,n =6 )。结论　DHAP可能通过开放钾通道而舒张肺内动脉平滑肌细胞 ,这可能是其降低肺动脉高压的重要机制之一。

Effect of 3,4-Dihydroxyacetophenone on delayed rectifier potassium current of the intrapulmonary artery smooth muscle cells in rats

AIM To study the effects of DHAP on potassium channel of smooth muscle cells METHOD Smooth muscle cells(PASMCs) of rat intrapulmonary arteries were obtained by an enzymatic dissociation method (papain and collagenase), delayed rectifier potassium current was determined and the effect of 3,4 Dihydroxyacetophenone (DHAP) was observed RESULTS ①When the PASMCs is clamped at -40 mV, depolarizing the membrane potential at increasing steps of 10 mV for a duration of 300 ms could evoke a series of outward potassium current without any deactivation, which was time and voltage dependent and showed delayed rectifier properties ②When command potential was +50 mV and +60 mV, 5 min after addition of 10 -6 mol·L -1 DHAP, this potassium current increased from (12 97±2 45), (16 83±3 28) pA/pF of control to (18 29±2 63), (22 90±3 21) pA/pF ( P<0 05, n =6). CONCLUSION DHAP may be an opener of K DR .