Role of glucocorticoid receptor in hepatic injury in early stage after severe multiple injury

AIM: To investigate the functions of GR in the course of hepatic secondary injury after severe multiple injury. METHODS: Rat model was produced by adopting severe thoracic impact injury accompanied with mono-side femur fracture, and glucocorticoid receptor was blocked before severe multiple injury. Hepatic macropathology and alterations under light microscope were examined. Maximal binding volume of glucocorticoid receptor (GR) in hepatic tissue was assayed by radio-ligand binding assay and protein content was assayed by Western blot. RESULTS: Maximal binding volume and protein content of GR were gradually decreased in hepatic tissue after severe multiple injury, obviously lower than that in normal control at 4 h after trauma (P＜0. 01), and the lowest value was at 12 h after trauma. Maximal binding volume was 12. 9% of normal control (P＜0. 01), and protein content was 21. 9% of normal control (P＜0. 01). In addition, no significant pathological alteration in liver was found after trauma. However, the pathological analysis showed that the administration of GR blocker before severe multiple injury could cause severe hepatic congestion and infiltration of inflammatory cells in hepatic sinusoid in a dose-dependent manner. CONCLUSION: GR insufficiency could cause secondary hepatic injury in early stage after severe multiple injury, implying an important role of GR in injury and anti-injury mechanism of hepatic tissue cells.