肝炎后肝硬化病人肝组织α_1-肾上腺素受体的定量研究

A quantitative study on α_1-adrenergic receptor of liver plasma membranes of cirrhotic pa- tients with portal hypertension

为观察肝硬化时α_1-受体变化及其与肝脏代谢和门肝血流动力学紊乱的关系,用放射配基结合分析法测定伴门静脉高压症的肝炎后肝硬化病人肝组织α_1-受体最大结合容量(Bmax)、组织受体最大含量(RMC)和平衡解离常数(Kd)。结果发现,9例肝炎后肝硬化病人肝组织α_1-受体的Bmax为129.1±12.0fmol/g蛋白,与对照组(8例,142.1±14.1fmol/g蛋白)无显著性差异(P>0.05),RMC为417.4±76.8fmol/g肝组织,较对照组739.0±167.6fmol/g肝组织为低(P<0.01);Kd值为0.3945±0.0974nmoi/L,较对照组(0.2382±0.0548nmol/L)明显增大(P<0.01)。结果提示,肝硬化病人肝组织α_1-受体数量和亲和力发生了变化,后者可能与肝硬化时的代谢紊乱和门脉高压症发病有关。

Radio ligand binding analysis was used to quantitatively measure the concentration and affinity of α_1-adrenergic receptor in the liver plasma membranes of the posthepatic cirrhotic patients with portal hypertension. It was found that, compared with 8 non-hepatopathy controls, the maximal binding capacity(Bmax) of 9 posthepatic cirrhotic patients decreased from 142.1±14.1 to 129.1±12.0 fmol/mg of protein (P>0.05) with increased dissociation constant(Kd) values (0.3945±0.0974 nM vs. 0.2382±0.0548 nM, P<0.01), and the receptor maximal content(RMC) plunged from 739.0±167.6 fmol/g to 417.4±76.8 fmol/g (P<0.01). These findings indicated that the decreased concentration and affinity of α_1-adrenergic receptor may play an important role in the disorder of metabolism of catecholamine often seen in some cirrhotic patients and have implications in the pathogenesis of portal hypertension.