薯蓣皂苷对大鼠心肌收缩与钠-钙交换体的影响  

The effects of dioscin on myocardial contraction and sodium-calcium exchanger

作　　者：杨帆[1] 韩钰[1] 丛恬駪[1] 康毅[1] 李燕[1] 孙凯[1] 尹永强[1] 娄建石[1] 

机构地区：[1]天津医科大学基础医学院药理学教研室,天津300070

出　　处：《中国应用生理学杂志》2016年第3期209-213,共5页Chinese Journal of Applied Physiology

基　　金：天津应用基础及前言技术研究计划青年项目(14JCQNJC13700)

摘　　要：目的:观察薯蓣皂苷(Dio)对大鼠心肌收缩作用以及胞内Ca^(2+)浓度的影响,并初步探讨其作用机制与Na^+-Ca^(2+)交换体(NCX)的关系。方法:采用Langendorff逆行主动脉灌流法对大鼠离体心脏进行灌流,利用压力感受器插管法测定左心室相关心功能参数,记录及其在应用NCX选择性抑制剂SEA0400情况下对左心室收缩压(LVSP)、左心室舒张末期压(LVEDP)、左心室内压最大上升/下降速率(±dp/dt_(max))以及心率(HR)的影响;利用激光共聚焦显微观察薯蓣皂苷及SEA0400对大鼠心肌细胞H9c2细胞内Ca^(2+)浓度的影响。结果:离体心脏灌流结果显示,1μmol/L Dio可显著增加LVSP,增加约19.7%(P<0.01);增加左室内压最大上升速率(+dp/dt_(max)),增加约9.6%;激光共聚焦测定Ca^(2+)荧光强度实验结果显示:1μmol/L Dio可使H9c2细胞中Ca^(2+)相对荧光强度增加(P<0.01);而在SEA0400存在的情况下,1μmol/L的Dio使细胞内Ca^(2+)相对荧光强度变为(17.09±0.63),给予Dio后差异有显著性(P<0.01)。在细胞液中无Ca^(2+)或无Na^+时,给予1μmol/L的Dio使Ca^(2+)相对荧光强度减小,与给予1μmol/L的Dio差异有显著性(P<0.01)。结论:Dio可增加左心室收缩压和最大上升速率,表现正性肌力作用;Dio可使细胞内Ca^(2+)浓度增加,其作用机制与增加Na^+内流,促进NCX反向转运有关。Objective： To investigate the inotropic effects of dioscin（Dio）in rat isolated-heart and intracellular free calcium concentration in isolated rat ventricular myocytes and to explore its mechanism preliminarily. Methods： Left ventricle contractile function was measured using the Langendorff non-recirculating mode of isolated rat heart perfusion. Effects of dioscin and dioscin ＋ SEA0400,sodium-calcium exchanger（ NCX） inhibitor,were investigated by measuring left ventricular systolic pressure（ LVSP） and left ventricular end diastolic pressure（ LVEDP）. Also,heart rate（ HR）,peak rate of rise / fall of left ventricular pressure（ ± dp / dt_（max）） of isolated rat heart were calculated; Effects of dioscin and SEA0400 on intracellular free calcium concentration in rat H9c2 cells were measured by Fluo3-AM and then detected the fluorescence intensity with confocal microscopy. Results： With 1 μmol / L dioscin,LVSP was significantly increased by 19. 7%（ P 0. 01） and dp / dt_（max）was increased by 9. 6%; With 1 μmol / L dioscin,the relative fluorescence intensity of intracellular free calcium concentrations were strong significantly（ P 0. 01）. While in presence of SEA0400,the relative fluorescence intensity was changed to 17. 09 ± 0. 63（ P 0. 01） by 1 μmol / L dioscin. With 1 μmol / L dioscin,the relative fluorescence intensity was weak（ P 0. 01） without calcium or sodium in the extracellular fluid. Conclusion： Dioscin shows positive inotropic effect on isolated rat heart,enhancing the LVSP and ＋ dp / dt_（max）; Dioscin increases the intracellular concentration of Ca^（2＋） in the cardiac myocytes by increasing Na~＋influx and facilitating the reverse mode of the sodium-calcium exchanger.

关 键 词：薯蓣皂苷 心肌 大鼠 正性肌力作用 Na^+-Ca^(2+)交换体 

分 类 号：R331.3[医药卫生—人体生理学]