To quantitatively measure the α1-adrenergic receptors and select the suitable conditions of receptor-ligand binding assay. Radioligand binding analysis was used to measure the concentration of α1-adrenergic receptors, and the measuring conditions were selected, respectively. Under the selected conditions, the α1-adrenergic receptors in lier plasma membranes of 8 nonhepatopathy subjects were measured.Under such suitable conditions as ３H-prazosin concentration 0.1-2.0nmol/L, incubating temperature 37℃, reaction time 20 minutes and seperating free ligand from system with double layer of filter paper, the binding of 3H-prazosin to α1receptors from 8 nonhepatopathy subjects were saturable with a high affinity. The Bmax, Kd, RMC and Hill coefficient were 142.1±14.1 fmol per milligram of protein, 0.2382±0.0548 nM, 739.0±167.6 fmol per gram of liver and 0.90±0.03, respectively.The suitable conditions may be very important for measuring α1-adrenergic receptors in human liver plasma membranes, which should be considered in hepatopathy studies.
