【摘要】 为探讨中药复方大川芎丸 (DCXW)与大鼠肝细胞膜上血管紧张素 的 型受体 (AT1 受体 )的相对结合亲和力 ,采用蔗糖密度梯度离心法制备大鼠肝细胞膜受体制剂。通过非标记配基饱和实验建立理想的受体结合分析系统。通过竞争取代反应分别确定洛沙坦 (L osartan)和 DCXW的 IC5 0 值 ,再计算得到 DCXW的相对结合亲和力。相对结合亲和力 =IC5 0 ,L osartan/ IC5 0 ,DCXW× 10 0 %。通过血压测定实验确定 DCXW是 AT1 受体激动剂还是拮抗剂。结果 :L osartan的 IC5 0 值为 6 .5× 10 - 3 m g/ m l;DCXW的 IC5 0 值为 3.6× 10 - 2 m g/ ml,相对结合亲和力为18.1% (相对于 L osartan)。DCXW有降压作用 ,它是 AT1 受体拮抗剂。以上结果表明 ,中药复方 DCXW能够同 1 2 5I Ang 竞争与大鼠肝细胞膜上的 AT1 受体结合 ,这与其降压和改善微循环的生理效应是一致的。更多还原

【Abstract】 DCXW is a composite of some traditional Chinese medicines.This study was designed to determine the relative binding affinity of DCXW for type 1 angiotensinⅡ(AngⅡ) receptor (AT 1 receptor) on rat liver membranes. The rat liver membranes were prepared by adopting the protocol of sucrose density gradient centrifugation. Optimal conditions for receptor binding analysis system were established by unlabeled ligand saturation experiment. Competitive displacement reactions were conducted to obtain IC 50 of Losartan and DCXW respectively. The relative binding affinity of DCXW was obtained according to the following equation: Relative binding affinity=IC 50,Losartan /IC 50,DCXW ×100%. Blood pressure determination was made to examine whether DCXW was an agonist or antagonist for AT 1 receptor. Results:IC 50, Losartan =6.5×10 -3 mg/ml; IC 50,DCXW =3.6×10 -2 mg/ml. Relative binding affinity of DCXW=18.1%. DCXW,as show, was an antagonist for AT 1 receptor by virtue of its bility to reduce blood pressure. These finding suggested that DCXW could compete with 125 I AngⅡfor the binding of AT 1 receptor on the rat liver membranes, which was consistent with its physiological effect on blood pressure.更多还原