Changes in glucocorticoid and mineralocorticoid receptors of liver and kidney cytosols after pathologic stress and its regulation in rats.

Abstract

As effectors, glucocorticoid and mineralocorticoid receptors play an important role in pathologic stress. This study was designed to observe the changes in glucocorticoid receptor of liver cytosols and mineralocorticoid receptor of kidney cytosols after pathologic stress in rats. Controlled laboratory study. Medical university. Male Wistar rats (weight range, 180-200 g). Rats received a low-degree or heavy-degree immersion scald that covered 10% or 35% total body surface area and were randomly divided to receive either tumor necrosis factor-alpha, interleukin-1beta polyclonal neutralizing antibody, alpha-melanocyte-stimulating hormone, KPV peptide (Ac-D-Lys-L-Pro-D-Val), or saline (control). The binding capacity and the apparent dissociation constant of the steroid-binding sites of normal, low-degree, and heavy-degree scalded rats were measured by radioligand-binding assay, with [3H]dexamethasone and aldosterone as the ligand, respectively. The binding capacity of glucocorticoid receptor in hepatic cytosols in rats 12 hrs after heavy-degree scald (208.45 +/- 30.78 fmol/mg of protein) was lower than that of the control group (306.71 +/- 27.96 fmol/mg of protein; p < .01). The binding capacity of glucocorticoid receptor in hepatic cytosols in rats 12 hrs after low-degree scald (296.64 +/- 16.06 fmol/mg of protein) was not significantly different compared with the control group (p > .05). There were two types of mineralocorticoid receptor in kidney cytosols in rats, and their binding capacity and apparent dissociation constant were not identical. The binding capacity of mineralocorticoid receptor in rats 12 hrs after heavy-degree scald (binding capacity 1, 22.40 +/- 5.40 fmol/mg of protein; binding capacity 2, 196.30 +/- 32.50 fmol/mg of protein) was lower than that of the control group (binding capacity 1, 41.60 +/- 7.20 fmol/mg of protein; binding capacity 2, 317.60 +/- 70.00 fmol/mg of protein; p < .01). The binding capacity of mineralocorticoid receptor in kidney cytosols in rats 12 hrs after low-degree scald (binding capacity 1, 41.40 +/- 5.00 fmol/mg of protein; binding capacity 2, 314.80 +/- 45.70 fmol/mg of protein) was not significantly different compared with the control group (p > .05). The injections of anti-rat tumor necrosis factor-alpha, interleukin-1beta polyclonal neutralizing antibody, alpha-melanocyte-stimulating hormone, and KPV peptide (Ac-D-Lys-L-Pro-D-Val) might prevent a reduction in the binding capacity of glucocorticoid receptor in hepatic cytosols and mineralocorticoid receptor in kidney cytosols in rats with heavy-degree scald in vivo. These studies suggest that the glucocorticoid receptor of hepatic cytosols and the mineralocorticoid receptor of renal cytosols decreased in rats with heavy-degree immersion scald and that the injections of anti-rat tumor necrosis factor-alpha, interleukin-1beta polyclonal neutralizing antibody, alpha-melanocyte-stimulating hormone, and KPV peptide might increase the level of glucocorticoid receptor and mineralocorticoid receptor in vivo.