THE RADIOLIGAND BINDING ASSAY OF GIUCOCORTICOID RECEPTOR IN THE HEPATIC CYTOSOL OF ADRENALECTOMIZED RATS / 第二军医大学学报

ABSTRACT

The specific glucocorticoid binding of adrenalectomized rats was measured by the radioligand binding assay.The [3H]dexamethasone was used as ligand.The binding capacity (R0) and dissociation constant (Kd) were calculated.The specific binding sites present the following characteristics 1.Low binding capacity , (R0 264?50 fmole/mg protein) ; 2.High affinity,(Kd2.5?0.9?10-8M) ; 3.The specificity of steroid binding ; 4.The presence in the other target organs , such as brain, kidney and thymus;5.The degree of saturation in vivo of the hepatic cytosol binding is closely correlated to the induction of hepatic enzymes, tyrosine aminotransferase.These indicate that the specific binding sites of dexamethasone are functionally significant glucocorticoid receptors of the rat liver cytosol.