羟苯氨酮激活家兔血管平滑肌细胞钙敏感钾通道

Activation of Ca^(2+)-activated K^+ channels by oxyphenamone in rabbit mesenteric vascular smooth muscle cells

目的 研究羟苯氨酮 (oxyphenamone ,Oxy)扩张血管作用机理。方法 用全细胞膜片钳技术 ,监测家兔肠系膜阻力血管平滑肌细胞钙敏感钾通道电流变化以及Oxy对其的影响。结果 0 1μmol·L- 1Oxy明显增加钙敏感钾通道电流 ,冲洗后恢复至给药前水平 ;0 0 1～ 10 μmol·L- 1Oxy明显增加钙敏感钾通道电流 ,且呈现浓度依赖性。

Aim To study the effects of oxyphenamone (Oxy) on activation of Ca 2+ -activate d K + channels in rabbit mesenteric vascular smooth muscle cells. Methods To measure the effect of Oxy on the Ca 2+ -activated K + channel (BK (Ca) channel) activity in rabbit mesenteric vascular smooth muscle cells by using who le cell patch clamp techniques. Results Oxy reversibly increase BK (Ca) channel activity in rabbit mesenteric artery smo oth muscle cells. Application of Oxy (0 1 μmol·L -1 ) to the perfusio n solution caused significant increase in outward currents and its effect was co mpletely abolished by washout; The outward currents K + was inhibited by TEA (7 5 mmol·L -1 ); Oxy activated the BK (Ca) channel in a dose-dependent manner (0 01-10 μmol·L -1 ). Conclusion Oxy directly increase the activity of BK (Ca) channel activity in rabbit mesente ric vascular smooth muscle cells in dose-dependent manner.