论文部分内容阅读
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。
In order to investigate the relative binding affinity of DCXW and angiotensin-type receptor (AT1 receptor) on rat hepatocyte membrane, rat hepatocyte membrane receptor preparations were prepared by sucrose density gradient centrifugation. An ideal receptor binding assay system was established by non-labeled ligand saturation experiments. The IC50 values of losartan and DCXW were determined by competitive substitution reactions, and the relative binding affinity of DCXW was calculated. Relative binding affinity = IC50, Losartan/IC50, DCXW 100%. It was determined by blood pressure assays whether DCXW is an AT1 receptor agonist or antagonist. RESULTS: The IC50 value of Losartan was 6.5 × 10 -3 mg/ml; the IC50 value of DCXW was 3.6 × 10 -2 mg/ml, and the relative binding affinity was 18.1% (relative to Losartan). DCXW has antihypertensive effect and it is an AT1 receptor antagonist. The above results indicate that DCXW, a Chinese herbal compound, can compete with 125I Ang for binding to AT1 receptors on rat hepatocyte membranes, which is consistent with its antihypertensive and microcirculatory physiological effects.