ALPHA-1-ADRENERGIC RECEPTORS IN LIVER PLASMA-MEMBRANES OF CIRRHOTIC-PATIENTS WITH PORTAL-HYPERTENSION - A QUANTITATIVE STUDY

Objective To investigate the changes of alpha-1 adrenergic receptors i n cirrhotic liver and the relationship between the changes and the pat hogenesis of portal hypertension. Methods The concentration and affini ty of alpha-1 adrenergic receptors in the liver plasma membranes of po sthepatitic cirrhotic patients with portal hypertension were quantitat ively measured using radioligand binding analysis. Results Compared wi th 8 controls without hepatic pathological changes, the maximal bindin g capacity (Bmax) of 9 posthepatitic cirrhotic patients decreased (129 .1@12.0 vs 142.1@14.1 fmol/mg protein, P > 0.05), dissociation constan t (Kd) values increased (0.3945 @ 0.0974 vs 0.2382 @ 0.0548 nmol/L, P < 0.01), and the receptor maximal content (RMC) decreased (417.4 @ 76. 8 vs 739.9 @ 167.6 fmol/g liver, P<0.01). Conclusions The decreased co ncentration and affinity of alpha-1 adrenergic receptors may play an i mportant role in the metabolic disturbances of catecholamines often se en in some cirrhotic patients, and have implications in the pathogenes is of portal hypertension.