治疗浓度哇巴因增强大鼠心室肌细胞收缩功能的机制研究

Study on the Mechanism of Enhanced Contractility of Ventricular Myocytes in Rats with Treatment Concentration of Ouabain

目的探讨治疗浓度(10-8mol/L)哇巴因对急性分离大鼠心室肌细胞收缩功能的影响及钠钾泵激活的相关信号转导通路是否参与了治疗浓度哇巴因的强心作用。方法采用酶解法急性分离大鼠心室肌细胞并复钙,可视化动缘探测系统检测单个大鼠心室肌细胞收缩功能。观察10^(-9)~10^(-4)mol/L哇巴因对急性分离大鼠心室肌细胞收缩力的影响。采用10^(-8)mol/L哇巴因分别与1μmol/L PP2、100μmol/L NAC、1μmol/L U73122、1μmol/L Xestospongin C和50μmol/L PD98059共同灌流,观察记录5种信号转导通路抑制剂对10^(-8)mol/L哇巴因强心作用的影响。结果10^(-9)~10^(-4)mol/L的哇巴因均能使急性分离大鼠心室肌细胞收缩力增强(P<0.01),且具有浓度依赖性。1μmol/L PP2、100μmol/L NAC、1μmol/L U73122及1μmol/L Xestospongin C均可部分抑制10^(-8)mol/L哇巴因的强心作用(P<0.05,P<0.01);但50μmol/L PD98059+10^(-8)mol/L哇巴因与10^(-8)mol/L哇巴因使大鼠心室肌细胞收缩幅度比较差异无统计学意义(P>0.05)。结论10^(-9)~10^(-4)mol/L的哇巴因均能够增强急性分离大鼠心室肌细胞收缩力。10^(-8)mol/L哇巴因的强心作用极有可能与钠钾泵激活的Src/EGFR/Ras/ROS信号转导通路和Src/EGFR/PLC/PIP2/IP3信号转导通路有关。

Objective To investigate the effect of treatment concentration(10^(-8) mol/L)of Ouabain on contractile function of acutely isolated ventricular myocytes of rats and to study whether the signal transduction pathway activated by sodium and potassium pump is involved in the cardiac strengthening effect of Ouabain.Methods Ventricular cardiomyocytes of rats were acutely isolated by enzymolysis and supplemented with calcium.The systolic function of single rat cardiomyocytes were detected by visual single-cell moving edge detection system.The effect of 10^(-9)-10^(-4) mol/L Ouabain on contractility of acutely isolated rat cardiomyocytes was observed.10^(-8) mol/L Ouabain was co-irrigated with 1μmol/L PP2,100μmol/L NAC,1μmol/L U73122 and 1μmol/L Xestospongin C,and 50μmol/L PD98059,respectively.The effect of 5 kinds of signal transduction pathway inhibitors on cardiotonic effect of 10^(-8) mol/L Ouabain was observed and recorded.Results The contractility of acutely isolated ventricular myocytes of rats was enhanced by 10^(-9)-10^(-4) mol/L Ouabain(P<0.01)in a concentration-dependent manner.1μmol/L PP2,100μmol/L NAC,1μmol/L U73122 and 1μmol/L Xestospongin C could partly inhibit the cardiotonic effect of 10^(-8) mol/L Ouabain(P<0.05,P<0.01).However,there was no significant difference in the contraction amplitude of ventricular myocytes between 50μmol/L PD98059+10^(-8) mol/L Ouabain and 10^(-8) mol/L Ouabain(P>0.05).Conclusion 10^(-9) to 10^(-4)mol/L Ouabain can increase the contractility of acutely isolated ventricular myocytes of rats.The cardiotropic effect of 10^(-8) mol/L Ouabain is most likely related to the Src/EGFR/Ras/ROS signal transduction pathway and the Src/EGFR/PLC/PIP2/IP3 signal transduction pathway activated by the sodium potassium pump.