颅脑外伤后神经细胞糖皮质激素受体表达变化与激素抵抗

Expression changes of glucocorticoid receptor and steroid-resistance in nerve cell following traumatic brain injury in rats

目的通过研究颅脑外伤后早期伤侧皮层细胞糖皮质激素受体(GR)表达的变化,探讨伤后糖皮质激素抵抗的时相特点,为临床外源性糖皮质激素的合理应用提供实验依据。方法采用Westemblot印迹分析法及放射配基结合分析法,检测大鼠伤后72h内伤侧皮层神经细胞核蛋白中GR表达的数量及其最大结合容量的变化情况。结果大鼠外伤后0.5hGR的表达即开始降低,12h降到最低,显著低于对照组(P<0.01),后逐渐回升,48h恢复至对照组水平,此后仍逐渐上升而高于对照组;伤后12hGR的最大结合容量开始下降,24h降至最低,此后逐渐回升,72h恢复至对照组水平。结论颅脑外伤后GR的数量及功能状态均明显下调,从而产生糖皮质激素效应抵抗现象。

Objective To explore the characteristics of glucocorticoid resistance following traumatic brain injury,and to provide experimental bases for proper use of the glucocorticoid by observing the expression changes of glucocorticoid receptor(GR) in nerve cell. Methods Western blot was used to detect the expression of the GR in nerve cell, and maximal combining volume of GR was observed during 72 hours after injury.Results The expression of the GR in nerve cell significantly decreased from 0. 5 hours after injury, reached the lowest at 12 hours (compared with control group, P<0.01),gradually recoverd to normal at 48 hours,and was much higher than that in control group after 72 hours. Maximal combining volume of GR gradually decreased from 12 hours after injury, reached the lowest at 24 hous, recoverd to normal at 72 hours. Conclusion The expression and maximal combining volume of the GR are significantly decreased after traumatic brain injury, which induces the effect of glucocorticoid resistance.