Glucocorticoid receptor quantification under low glucocorticoid level conditions.

The raised GR level in adrenalectomy may be a functional adaptation to the low hormone conditions and is suggested that the liver GR level may be regulated by the negative feed back mechanism.

Abstract

Disturbances in the glucocorticoid hormone serum level lead to dramatic, frequently lethal changes in mammalian organism (Addison's disease, Cushing's syndrome). Hypofunction of adrenal glands (hypocorticism) was simulated by bilateral adrenalectomy of male Wistar rats. Changes in the liver cell glucocorticoid receptor (GR) content were followed throughout 2 hrs to 8 days in the postoperative period, by the quantitative Western blot method and by the synthetic steroid equilibrium binding method of Scatchard. The results of our measurements showed: 1, 1.5 to 2 fold increase in the rat liver GR protein of adrenalectomized animals in respect to the appropriate controls. 2. the increase in the GR protein occurs already 2 hours after the operation and remains at the increased, plateau values throughout the time period studied. It is suggested that the liver GR level may be regulated by the negative feed back mechanism. The raised GR level in adrenalectomy may be a functional adaptation to the low hormone conditions.