血管钠肽对大鼠腹主动脉平滑肌细胞ATP敏感钾通道的作用

Effects of vasonatrin peptide on ATP-sensitive potassium channel of abdominal aortic smooth muscle cells in rats

目的观察血管钠肽(VNP)对大鼠腹主动脉的舒张作用及对ATP敏感性钾通道(ATP-sensitive potassium channel,KATP)的作用。方法采用离体血管灌流方法,测定VNP对血管环张力的影响。采用膜片钳方法观察VNP对KATP通道的影响。结果 VNP对大鼠的腹主动脉具有浓度依赖性舒张作用,该作用无内皮依赖性:VNP对内皮完整的腹主动脉最大舒张率(Emax)为(81±8)%,对内皮缺失腹主动脉Emax为(74±6)%。在浴槽内预先孵育优降糖(1×10^(-6) mol/L)可降低血管对VNP的舒张效应。VNP可增强腹主动脉血管平滑肌细胞K_(ATP)通道电流:VNP(1×10^(-6)M)增强K_(ATP)通道Emax为(112±24)%,优降糖(1×10^(-6)mol/L)可消除这一作用。结论 VNP有舒张血管作用,这一作用与增强K_(ATP)通道电流有关。

AIM To observe the effects of vasonatrin peptide （VNP） on rat abdominal aorta and on ATP-sensitive potassium channels （ATP-sensitive potassium channel, KATe ）. METHODS Isolated vascular perfusion method was used to determine the effects of VNP on vascular tension and patch clamp was used to observe the effects of VNP on KATP channel. RESULTS VNP evoked concentration-dependent and endothelium-independent relaxations on isolated abdominal aortic artery. Emax of VNP on endothelium intact abdominal aortic artery was （81± 8 ）% and Emax on endothelial denuded abdominal aortic artery was （74 ±6）%. The relaxations induced by VNP on blood vessels were attenuated by preincubation in organ chambers with glibenclamide （ 1x l0 -6 mol/L）. VNP enhanced KATP channel currents of abdominal aortic vascular smooth muscle cell. Emax of VNP （1 x10-s M） reinforced KATP channel currents was （112 ±24）%, and the effects were eliminated by glibenclamide （1 xl0-6 tool/L）. CONCLUSION VNP is an effective vasorelaxing peptide whose action is caused by enhancing currents of ATP-sensitive potassium channel.