Ali M, Allen H R, Vedeckis W V, Lang C H
Gene Expression Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808.
Life Sci. 1991;48(7):603-11. doi: 10.1016/0024-3205(91)90534-i.
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.
在皮下注射大肠杆菌24小时后,对正常(注射生理盐水)和高代谢脓毒症大鼠的肝脏、大脑和肌肉中的糖皮质激素受体(GR)激素结合活性、其物理特性以及GR mRNA水平进行了研究。脓毒症大鼠肝脏、大脑和肌肉细胞溶质中的GR水平(激素结合活性)分别下降了约40%、56%和40%。在肝脏中研究了脓毒症时GR水平降低的机制。即使在给予大肠杆菌48小时后,GR水平仍保持较低(为对照激素结合水平的45%)。肝脏GR的降低发生在9S未转化的GR中。脓毒症肝脏的9S GR以与对照肝脏GR相当的比例转化为4S形式。此外,对照和脓毒症肝脏的4S GR与DNA纤维素的结合能力相似。脓毒症肝脏中的GR mRNA水平下降了约30%。因此,脓毒症时GR激素结合活性的降低似乎是由于GR mRNA稳态水平的下降,而非GR蛋白定性特性的改变。