人参皂甙逆转糖皮质激素下调其受体的实验研究

目的 观察人参皂甙(GS)对糖皮质激素(GC)下调其受体(GR)的影响,并探讨其作用途径.方法 建立大鼠肝总动脉结扎模型,分别给予GS和地塞米松(DEX)等药物干预,观察术后12 h各组血清皮质酮、肝脏GR最大结合容量(GR Bmax)、平衡解离常数(K<,d>)和GR mRNA水平.结果 GS组和模型组皮质酮水平明显高于GS+DEX组、DEX组和正常组(均P<0.01),GS+DEX组和DEX组皮质酮水平明显高于正常组(均P<0.01);GS组GR Bmax高于模型组(P<0.05),Gs+DEX组GR Bmax明显低于模型组(P<0.05),但高于DEX组(P<0.01);GS组GR mRNA表达明显高于模型组(P<0.01),DEX组则低于模型组、正常对照组和GS+DEX(P<0.01).结论 GS虽然对肝缺血损伤大鼠血清皮质酮水平无影响,但可以部分逆转GC对GR的下调作用.

Experimental study of ginsenosides in reversing the down-regulation of glucocorticoids on glucocorticoid receptor

Objective To observe the effect of ginsenosides (GS) on the action of glucocorticoid (GC) in down-regulating glucocorticoid receptor (GR), and to explore the mechanism. Methods The rat model with hepatic artery ligation (HAL) was established and treated with GS and dexamethasone (DEX). Serum corticosterone level, maximal GK binding capacity (GR Bmax), K<,d> and GR mRNA in liver cells were detected 12 h after HAL. Results The levels of corticosterone in GS group and model group were higher than those in GS + DEX group, DEX group and normal group (all P < 0.01). The levels of corticosterone in GS + DEX group and DEX group were higher than that of normal group (both P <0.01). Compared to model group, GR Bmax in GS group was higher (P < 0.05), GR Bmax in GS + DEX group was lower (P < 0.05), but higher than that of DEX group (P <0.01). The expression of GR mRNA in GS group was significantly higher than model group (P < 0.01), but GR mRNA expression in DEX group was lower than that in model group, normal group and GS + DEX group (P <0.01). Conclusion GS partially reverses the down-regulation of GC on GR Bmax and GR mRNA, but it has no effect on serum corticosterone level in the rat model with HAL.