1-磷酸鞘氨醇对豚鼠心室肌细胞钙电流的影响

Effects of sphingosine-1-phosphate on calcium current in isolated ventricular myocytes of guinea pig

目的 :研究 1-磷酸鞘氨醇 (S1P)对心室肌细胞膜钙离子通道的作用及机制。方法 :L angendorff离体心脏逆向灌流法分离豚鼠心室肌细胞 ,随机选取心室肌细胞分为正常对照组和 S1P0 .1、 1.0和 10 .0 μmol· L- 1 剂量组以及百日咳毒素 (PTX) 0 .1m g· L- 1 +S1P1.0 μm ol· L- 1 组。采用全细胞膜片钳技术分别记录各组心室肌细胞 Ca2 + 电流。结果 :1.0 μmol· L- 1 的 S1P使豚鼠心室肌细胞 Ca2 + 电流从给药前的 (0 .2 5 6± 0 .0 30 ) m V增加到(0 .36 7± 0 .0 90 ) m V (P<0 .0 5 ) ,10 .0 μm ol· L- 1 的 S1P使 Ca2 + 电流从给药前的 (0 .2 4 2± 0 .0 30 ) m V增加到(0 .36 4± 0 .0 6 0 ) m V (P<0 .0 1) ,而加入 G-蛋白耦联受体阻断剂 PTX后 ,S1P对 Ca2 + 通道电流的作用与给药前比较差异无显著性。结论 :S1P通过与 G-蛋白耦联的细胞膜受体介导促进豚鼠心室肌细胞 Ca2 + 通道的开放 ,并具有一定的剂量依赖性。

Objective To study the effects of sphingosine-1-phosphate(S1P) on calcium current of ventricular myocytes and its mechanisms. Methods The Langendorff perfusion method was used to isolate the ventricular myocytes of guinea pig and the ventricular myocytes of guinea pig were randomly divided into one control group, three S1P groups with dosages of 0.1, 1.0, and 10.0 μmol·L -1, and group of PTX 0.1 mg·L -1 together with S1P 1.0 μmol·L -1. The whole cell voltage clamp technique was used to record the calcium current of isolated ventricular myocytes of guinea pig. Results S1P 1.0 μmol·L -1 enchanced the calcium current from (0.256±0.030)mV before administration to (0.367±0.090)mV after administration (P<0.05). S1P 10.0 μmol·L -1 enchanced the calcium current from (0.242±0.030)mV before administration to (0.364±0.060)mV after administration(P<0.01). The effects of S1P to enchance the calcium current was blocked by PTX, a G protein-coupled receptor blocking agent. Conclusion S1P can promote the opening of calcium channels of the ventricular myocytes by G protein-coupled membrane receptor in a dose-dependence manner.