粉防已碱对大鼠血压、血浆肾素活性和心室乳头肌及门静脉收缩的影响

Effects of Tetrandrine on Hood Pressure, Plasma Renin Activity and the Contractility of the Ventricular Papillary Muscle and Portal Vein in Rats

在麻醉的SD雄性大鼠上,观察到粉防己碱(Tetrandrine,Tet)30mg/kg 2/d,ig连续4d能显著地降低血压,而对心率和血浆肾素活性(PRA)无明显影响。一次静注Tet 15 mg/kg,血压降低的同时伴有心率减慢,也不影响PRA。先用Tet连续灌胃4d后的动物,一次静注Tet引起同等程度的降压效应,说明Tet的降压作用无耐受现象。在离体实验中发现,Tet抑制电刺激引起的心室乳头肌收缩及门静脉纵条的自主收缩,EC_(50)分别为5.33×10^(-6)mol/L和4.25×10^(-5)mol/L,Tet的血管选择性为0.12。

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.