THE DETERMINATION OF THE GLUCOCORTICOID RECEPTOR IN THE HEPATIC CYTOSOL OF INTACT RATS AND THE CHANGES OF THE RECEPTORS AFTER SCALDING / 第二军医大学学报

ABSTRACT

The glucocorticoid receptor of hepatic cytosol of rat was determined by the exchange assay in the presence of endogenous corticosterone. The condition of ex-chame was 0℃ , 4.5~5 hours. The dissociation of corticosterone-receptor complex was about 90% under such a condition. The effect of the endogenous corticosterore on the assay was evaluated by the measurement of [3H]-dexamethasone binding after preincubation of the liver cytosol from adrenalectomized rats with different amounts of corticosterone. The results indicated that, at a corticosterone concentration of less than 6 nM the error of the specific binding capacity (Ro) of [3H]-dexa-methasone was no more than 10%,and the apparant dissociation constant (Kd) was essentially unchanged. The Ro and Kd of glucocorticoid receptor of the hepatic cytosol of normal and scalded rats were measured by this method. The Ro was decressed in the scalded rats. The levels of Ro in hepatic cytosol from rats after 1, 12,24, 36 hours and 5 days of scalding were 76.4?15.2%,70.6?22.0%79.7?5.8%, 113.0?24.8% and 102.9 ?17.6% (mean?SD) of the control group respectively. The apparant Kd slightly increased 1 hour after scalding. The possible mechanisms of the above changes were discussed.