1-磷酸鞘氨醇对心肌细胞钾离子通道的作用

THE EFFECTS OF SPHING-1-PHOSPHATE(S1P)ON THE POTASSIUM CHANNEL OF THE VENTRICULAR MYOCYTES

目的:研究1-磷酸鞘氨醇(S1P)对豚鼠心室肌细胞延迟整流钾电流(IK)、内向整流钾电流(IK1)的作用。方法:实验用胶原酶酶解法急性分离豚鼠心室肌细胞,利用全细胞膜片钳的方法记录心室肌细胞的延迟整流钾电流(IK)、内向整流钾电流(IK1)。结果:①应用S1P(1.1μmol/L)后IK从(1.2±0.26)nA降至(0.95±0.23)nA(P<0.01,n=6),而S1P(2.2μmol/L)组IL从(1.43±0.31)nA下降到(1.02±0.28)nA,统计学有显著性差异(P<0.01,n =6)。而S1P(1.1μmol/L)+苏拉明(Suramin)(200μmol/L)组与对照相比,IK峰值从(1.29±0.26)nA下降(1.26±0.37)nA,统计学无显著性差异(P>0.05,n=6)。②应用S1P(1.1μmol/L,2.2μmol/L)后与对照组比较,S1P (1.1μmol/L,2.2μmol/L)分别使内向整流钾电流(IK1)峰值从(-8.94±2.01)nA和(-8.81±1.55)nA下降到(-8.86±1.59)nA和(-8.55±1.39)nA,统计学无显著性差异(P>0.05,n=6)。结论:S1P可降低豚鼠心室肌细胞延迟整流钾电流(IK)的幅值,同时S1P对豚鼠心室肌细胞内向整流钾通道(IK1)没有作用。

Aim： To study the effect of Sphingosine-1-phosphate on the delayed rectifier potassium current（IK） and the inward rectifier potassium current（ IK1 ） of guinea pig isolated ventricular myocytes. Methods： Whole cell patch clamp technique was applied to record the delayed recti- fier potassium current and the delayed rectifier potassium current of guinea pig isolated ventricular Inyocytes. Results： （1）IK of SIP（ 1.1μmol/ L） decreased from （1.2± 0.26）hA to （0.95± 0.23）nA. While IK of S1P（2.2μmol/L） decreased from （1.43 ± 0.31）nA to （1.02 ± 0. 28） nA. There was significant difference compared to control group（ P 〈 0.01, n = 6）. The IK peak value was decreased from （ 1.29 ± 0.26） nA to （1.26 ± 0.37）nA at the group of S1P（1.1 μmol/L） plus suramin（200 μmol/L） and showed no significant difference compared to control group（ P 〉 0.05, n = 6）. （2）IK1 of S1P（ 1.1 μmol/L） decreased from （-8.94 ± 2.01）nA to （-8.81 ± 1.55）nA. While IK of S1P（2.2 μmol/L） decreased from （-8.86± 1.59）nA to （-8.55 ± 1.39）nA. There was no significant difference compared to control group（ P 〉 0.05, n = 6）. Conclusion： S1P inhibits delayed rectifier potassium current of ventricular myocyte in guinea pig remarkably, SIP shows no effects on delayed rectifier potassium current of ventricular myocyte in guinea pig.