碘化N-正丁基氟哌啶醇对大鼠胸主动脉平滑肌钾通道作用的研究

目的　研究碘化N 正丁基氟哌啶醇 (F2 )对大鼠胸主动脉平滑肌细胞膜钾通道的作用。方法　①采用全细胞膜片钳技术 ,测定不同浓度F2 作用时单个酶消化分离平滑肌细胞的钾电流 ;②采用大鼠胸主动脉环生物鉴定法 ,测定F2对KCl诱导动脉环收缩的作用以及格列苯脲对F2 扩血管作用的影响。结果　当钳制电压为 - 4 0mV ,去极化电位从 -3 0mV到 + 10 0mV ,步阶脉冲为 10mV ,刺激脉宽为 4 0 0ms的方波钳制方案进行刺激时 ,可记录到外向电流 ,此电流具有电压依赖性。在去极化电位为 + 70mV时 ,3种浓度( 0 1、1和 5 μmol·L-1)F2 使外向电流分别从给药前 ( 2 2 9±2 8)pA、( 2 2 6± 5 7) pA和 ( 2 2 8± 4 2 ) pA升到给药后 ( 3 5 4± 2 9)2 0 0 0 12 2 1收稿 ,2 0 0 1 0 6 10再修回 国家新药研究基金 (No 96 90 1 0 5 2 31)和国家自然科学基金 (No30 0 70 30 4)资助1 汕头大学医学院药理学教研室 ,汕头　 5 15 0 31作者简介 :韦日生 ,男 ,31岁 ,硕士研究生。Tel:0 10 62 0 9114 5 ,E mail:rswei@yahoo .com ;石刚刚 ,男 ,44岁 ,教授 ,硕士生导师pA (n =6,P <0 0 1) ,( 5 0 3± 86) pA (n =5 ,P <0 0 1)和( 986± 4 5 )pA (n =5 ,P <0 0 1)。 10 μmol·L-1格列苯脲对F2 增加的外向电流没有影响 ,10mmol·

Effect of N-n-butyl haloperidol iodide on potassium channel in smooth muscle cells and rings of rat aorta

AIM To investigate the effect of N n butyl haloperidol iodide (F 2) on potassium currents in enzymatically isolated vascular smooth muscle cells (VSMC) from thoracic aortas and the effect of F 2 on aortic rings of rat. METHODS The whole cell patch clamp technique and the contraction of rats thoracic aortic rings were used in experiments. RESULTS The outward currents were observed when holding potential was -40 mV and the cell was depolarized from -30 mV to +100 mV (in 10 mV increase) for 400 ms. At the point of the test potential of +70 mV, solutions of F 2 (0 1,1, 5 μmol·L -1 ) were added into bath (external) solution, which led to the increase of the outward currents from (229±28)pA,(226±57)pA and(228±42) pA to (354±29) pA ( n =6, P< 0 01) , (503±86) pA ( n =5, P< 0 01) and(986±45) pA ( n =5, P< 0 01), respectively. The outward currents were not inhibited with 10 μmol·L -1 glibenclamide but were inhibited significantly with 10 mmol·L -1 TEA. The 80 mmol·L -1 and 30 mmol·L -1 KCl induced aortic rings contraction were inhibited significantly with 10 μmol·L -1 F 2, respectively. The relaxation effect of F 2 on the aortic rings was unaffected with the K ATP blocker glibenclamide (10 μmol·L -1 ). CONCLUSION F 2 can open the potassium channels in ASMCs; but these potassium channels may not be K ATP .