Effects of Tetrandrine on Hood Pressure, Plasma Renin Activity and the Contractility of the Ventricular Papillary Muscle and Portal Vein in Rats / 第二军医大学学报

ABSTRACT

The effects of tetrandrine (Tet) on blood pressure, plasma renin activity (PRA) and the contractility of the papillary mascle and portal vein were studied in rats. After 4 d administration of Tet 30 mg/kg, 2/d, ig, blood pressure was decreased markedly in anesthetized male SD rats, but there were no effects on heart rate and PRA. A single dose of Tet 15 mg/kg iv reduced blood pressure and heart rate significantly, while did not change PRA. This single dose produced similar hypotensive effect in rats with and without pretreatment of Tet 30 mg/kg, 2/d, 4d, indicating the absence of tolerance. Tet inhibited the paced papillary muscle contractility and the spontaneous portal vein contractility, and the EC50 were 5.33?10-6mol/L and 4.25?10-5 mol/L, respectively. So the vascular selectivity of Tet is 0.12.