Expression difference of cerebral cortex and liver glucocorticoid receptors at protein level following severe closed traumatic brain injury in awake mice / 中华创伤杂志

ABSTRACT

Objective To study the relationship of expression of central cortex glucocorticoid receptor (GR) at protein level with GR expression in the liver at protein level and with changes of serum cortisol and adrenocorticotropic hormone (ACTH) following severe closed traumatic brain injury (TBI) in mice. Methods Severe TBI was established in awake mice by using a BIM-Ⅲ biomechanical machine. At 0.5, 2, 8, 24, 48 and 72 hours after TBI, the total cytosolic GR in the cortex and liver were detected with Western blotting. Levels of serum ACTH and cortisol were measured by ELISA technique and radio-immunological assay (RIA) respectively. Results The expression of GR both in the cortex and liver were obviously down-regulated at protein levels at 2-72 hours after TBI and increased slowly eight hours after injury. The GR in the liver showed no recovery at 72 hours after injury and that in the cortex was decreased continually at 24 hours after injury. Serum ACTH and cortisol levels were increased markedly compared with control group, when there were two different peaks in the observation curve.Conclusion There is glucocorticoid resistance both in the central and peripheral tissues after severe closed TBI in the awake mice, which changes in a time-dependent manner.