盐酸埃他卡林对正常大鼠肺内动脉平滑肌细胞钾电流的影响

Effects of Iptakalim Hydrochloride on Potassium Currents in Isolated Vascular Smooth Muscle Cells Derived from Rat Intrapulmonary Arteries

目的 观察盐酸埃他卡林 (Iptakalimhydrochloride ,Ipt)对大鼠动脉平滑肌细胞钾电流的作用。方法 用胶原酶I消化、分离大鼠肺内动脉平滑肌细胞 ,用全细胞记录 (wholecellrecording)技术记录细胞钾电流 ,通过浴槽内给药 ,观察药物对钾电流的影响。结果 以给药前记录钾电流为 10 0 % ,在给予盐酸埃他卡林 1.0、10 0 .0 μmol·L-1后 ,1min记录的钾电流幅度分别为(114 .9± 3.8) % (n =8)和 (114 .0± 3.5 ) % (n =5 ) ,与溶媒对照组 (87.0± 3.5 ) % (n =8)相比 ,有显著性差异 (P <0 .0 1)。在相同条件下给予吡那地尔 (Pinacidil) 1.0 μmol·L-1后 ,钾电流幅度为 (93.6± 4 .1) % (n =8) ,与溶媒对照组相比无显著性差异(P >0 .0 5 ) ;但当吡那地尔浓度增加到 10 0 .0 μmol·L-1时 ,钾电流幅度为 (12 8.1± 13.3) % (n =4 ) ,与溶媒对照组相比有显著性差异 (P <0 .0 1)。结论 Ipt对动脉平滑肌细胞钾电流有增强作用。

Aim To investigate the effects of iptakalim hydrochloride(Ipt) on potassium currents in isolated vascular smooth muscle cells derived from rat arteries.Methods Single isolated smooth muscle cells from rat intrapulmonary artery were obtained with collagenaseⅠdigestion methods.Under the whole-cell patch clamp conditions,the effects of Ipt on potassium currents were observed after drug application in the bath.Results When the potassium currents before Ipt application were thought to be 100%,the amplitudes of the outward potassium currents were increased to (114.9±3.8)%(n=8) and (114.0±3.5)%(n=5),by Ipt at the concentrations of 0.1μmol·L -1 and 1.0μmol·L -1 respectively,which were statistically significant compared with the vehicle groups(87.0±3.5)%(P<0.01,n=8).Under the same experimental conditions,the amplitude of the currents was (93.6±4.1)%(n=8) after application of pinacidil,an established K + channel opener,at the concentration of 1.0μmol·L -1 ,which were not statistically significant compared with that of the vehicle treated groups.But with the concentration of 100.0μmol·L -1 ,pinacidil could significantly increase the outward currents to (128.1±13.3)%(n=4) compared with the vehicle groups.Conclusion The results showed that Ipt could promote the potassium currents elicited on vascular smooth muscle cells.