实验性肝硬变形成过程中肝组织α_1－肾上腺素受体的定量研究

quantitative study on alpha-1 adrenergic receptor inthe liver of wistar rats during the process of CCl_4-in-duced hepatic cirrhosis

用放射配基结合分析法对Ｗｉｓｔａｒ大鼠四氯化碳性肝硬变形成过程中肝组织肾上腺素受体作了定量测定。实验分对照组（１０只）、肝纤维增生组（１３只）和肝硬变组（２０只）三组进行。与对照组相比，肝纤维增生组大鼠肝组织。受体的最大结合容量（Ｂｍａｘ）明显减少（１３２．８±２５．０ｆｍｏｌ／ｍｇ与９６．９±２０．８ｆｍｏｌ／ｍｇ蛋白，Ｐ＜０．０１），平衡解离常数（Ｋｄ）明显增大（０．１６３３±０．０３２２ｎＭ与０．３０７９±０．０７８６ｎＭ，Ｐ＜０．０１）；肝硬变组的Ｂｍａｘ也显著下降（１３２．８±２５．０ｆｍｏｌ／ｍｇ与７１．９±１７．７ｆｍｏｌ／ｍｇ蛋白，Ｐ＜０．０１），Ｋｄ值增大更为明显（０．１６３３±０．０３２２ｎＭ与０．４０１２±０．０９６５ｎＭ，Ｐ＜０．０１）。说明在肝硬变形成过程中，肝组织α＿１－受体的结合容量和亲和力受到了损害，后者在肝硬变患者儿茶酚胺的代谢紊乱及门静脉高压的形成中可能起着一定的作用。

Abstract In this study, radioligand binding analysis wasused to ouantitativelv measure the concentration andaffinity of alpha-1 adrenergic receptor in the liver ofWistar rats during the process of CCl_4-induced liver cir-rhosis.It wa;found that cornpared with normal con-trols, the maximal binding capacity(Bmax)of alpha-ladrenergic receptor in the liver of 13 pre-cirrhotic ratsdecreased from 132.8±25.0fmol/mg to 96.9±20.8fmol/mg of protein(P<0.01)with increased dis-sociation constant (Kd、from 0.1633±0.0322nM to0.3079±0.0786nM,P<0.01).TheBmax in 20 cir-rhotic rats decreased significantly from 132.8±25.0 fmol/mg to 71.9±17.7fmol/mg of protein(P<0.01),while Kd values increased from 0.1633±0.0322nM to 0.4012±0.0965nM(P<0.01).Thesefindings indicate that the decrease of binding capacityand affinity of alpha adrenergic receptor may play a rolehthe disterbances of metabolism of catecholamine of-ten seen in some cirrhotic patients and have implica-tions in the pathogenesis of portal hypertension。