关键词: 药理学, 蒺藜皂苷, 心脏, 药物作用, 血流动力学, 心肌收缩, 钙通道

Abstract: 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 Ca²⁺ 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.

Key words: pharmacology, Gross Saponins of Tribulus Terrestris, heart, drug effects, hemodynamics, myocardial contraction, calcium channels