Depletion of rat liver glucocorticoid receptor hormone-binding and its mRNA in sepsis

Abstract

Glucocorticoid receptor (GR) hormone-binding activity, its physical characteristics, and GR mRNA levels were studied in the liver, brain and muscle of normal (saline-injected) and hypermetabolic septic rats 24 h after the subcutaneous injections of E. coli . The GR levels (hormone-binding activity) declined by about 40%, 56%, and 40% in septic liver, brain, and muscle cytosol, respectively. The mechanism of the decrease in the GR levels in sepsis was studied in liver. The GR levels remained low (45% of control hormone-binding) even after 48 h of E. coli administration. The decrease in the liver GR occurred in the 9S untransformed GR. The 9S GR from septic liver transformed to the 4S form in proportions comparable to the control liver GR. In addition, the 4S GR from control and septic liver was capable of binding to DNA-cellulose to a similar extent. The GR mRNA level in septic liver declined by about 30%. Thus, a decrease in GR hormone-binding activity in sepsis appears to be due to a decline in the steady-state GR mRNA level and not from a change in the qualitative properties of the GR protein.