Effects of corticosterone on transcriptional activity of regenerating hepatocytes in the rat

The effect of corticosterone on transcriptional activity in regenerating hepatocytes of rat after partial hepatectomy (PH) was studied by using nucleolar organizer region associated proteins (AgNOR) staining as marker. The results showed that: during 0-24 h after PH, the numbers of AgNOR decreased whatever in sham adrenalectomized rats, adrenalectomized rats or adrenalectomized rats treated with corticosterone. The numbers of AgNOR in sham operated rats peaked at 36 h after PH, and then restored the pre PH level at 48 h. AgNORs increased constantly 24-48 h after PH in adrenalectomized rats. After the treatment of corticosterone at a dose of 10 or 20 or 40 mg/kg body weight respectively in the adrenalectomized rats, it was found that at 36 h and 48 h post PH, the more corticosterone used, the less the AgNORs appeared and the faster the ranger of AgNORs declined. RU486, the glucocorticoid receptor antagonist, was given subcutaneously at a dose of 10 mg/kg body weight 12 h before PH in order to investigate extensively the action of endogenous corticosterone. The similar results were observed in the adrenalectomized rats. These findings suggested that transcriptional activity in regenerating hepatocytes of rat was inhibited by corticosterone. This phenomenon appeared mainly at 24 h following PH via the binding of corticosterone to its receptor.