蒺藜皂苷对大鼠离体心脏血液动力学的影响

目的：观察蒺藜皂苷（GSTT）对大鼠离体心脏血流动力学的影响。 方法：采用Langendorff离体心脏灌流方法，以动脉血压（AP）、左室收缩压（LVSP）、左室舒末压（LVEDP）、室内压最大上升速率（+dp/dt_max）、室内压最大下降速率（-dp/dt_max）及心率（HR）、主动脉流量（AF）、冠脉流量（CF）8项血流动力学参数为指标，观察GSTT对心肌收缩性能的直接影响。结果：给药后5~20 min，100、150和200 mg?L^-1 3个剂量组GSTT均可使AP、LVSP、±dp/dt_max、AF的绝对值降低，使 LVEDP、CF的绝对值升高，与对照组比较差异均有显著性（P<0.05或P<0.01 ）；GSTT 3个剂量组均可拮抗因细胞外液钙离子浓度增加所致的正性肌力作用，同时拮抗因细胞外液葡萄糖浓度降低所致的心肌收缩力减弱，与对照组比较差异均有显著性（P<0.05或P<0.01）。 结论：GSTT可使离体工作心脏产生剂量依赖性的负性肌力作用，同时增加正常离体大鼠心脏冠脉流量，其负性肌力作用可能与阻滞钙通道有关，且这种负性肌力对心肌缺糖具有保护作用。

Effects of Gross Saponin of Tribulus Terrestris on cardiac hemodynamics in isolated working rat heart

Objective To observe effects of Gross Saponin of Tribulus Terrestris (GSTT) on cardiac hemodynamics in isolated working rat heart. Methods The direct effects of GSTT on myocardiac contractility were observed by a pattern of Langendorff isolated,perfused Wistar rat heart through determining the hemodynamics parameters including aorta flow (AF), coronary flow (CF), heart rate (HR), arterial blood pressure(AP), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), and ±dp/dt max . Results The LVSP,±dp/dt max,AP, and AF were decreased as well as the LVEDP, CF were increased 5-20 min after the perfusion of GSTT with the doses of 100,150, and 200 mg·L -1 compared with normal control, the differences were significant(P<0.05 or P<0.01). GSTT could decreased cardiac contractility and expanded coronary in a dose-dependent manner. Meanwhile, the GSTT decreased the positive inotropic effect of higher Ca 2+ by its negative inotropic effect and increased contractility of lower glucosi cardiac. Conclusion GSTT may cause negative inotropic effect in isolated working heart in a dose-dependent manner. The negative inotropic of GSTT may be related to its action of blocking the calcium channel and has protective effect on lower glucosi cardiac.