人参茎叶皂苷对失血性休克大鼠糖皮质激素受体的影响

Effects of ginsenosides on glucocorticoid receptor in hemorrhagic shock rats

目的 观察人参茎叶皂苷 (ginsenosides,GSS)对失血性休克大鼠糖皮质激素受体 (GR)的影响 ,并分析其作用机制 ,为研制及时抢救失血性休克患者的天然药物制剂提供实验依据。方法 雄性SD大鼠随机分为失血性休克组和对照组 ,失血性休克组分别每日ig 2 0 0 ,10 0 ,5 0mg/kgGSS水溶液 ,对照组和模型组ig蒸馏水 2mL ,共10d。以 [3 H]地塞米松为配体 ,用一点分析法测脑和肝胞液GR结合活性 (Rs)、半定量RT PCR方法测肝胞液GRmRNA水平、放免法测血浆促肾上腺皮质激素 (ACTH)和皮质酮 (GC)浓度。结果 GSS组大鼠脑和肝胞液的GR结合活性高于单纯失血性休克组 ,其中以中剂量组最明显 (P <0 0 1) ;GSS组大鼠肝胞液GRmRNA表达水平高于单纯失血性休克组 ;GSS组大鼠血浆ACTH和GC浓度和单纯失血性休克组没有明显差别。结论 GSS可减轻失血性休克大鼠GR结合活性的下降幅度 ,作用机制可能与其促进了GRmRNA表达有关 ,并可能存在一个最佳剂量。

Object To evaluate the effects of ginsenosides (GSS) in stem and leaves of ginseng on glucocorticoid receptor (GR) in the hemorrhagic shock rats, and study the mechanism. Methods Rats were divided into hemorrhagic shock group and control group. The rats in hemorrhagic shock groups were ig 200, 100, 50 mg/kg/d GSS, model group and control group were ig distilled water 2 mL for 10 days. The Rs of GR in brain and hepatic cytosol of rats were measured by radioligand binding assay, using [ 3H] dexamethasone as the ligand. The level of GR mRNA expression in hepatic cytosol were determined by RT-PCR. Plasma adrenocorticotrophic hormone (ACTH) and glucocorticoid (GC) concentrations were determined by the radioimmunoassay. Results Rs of GR in brain and hepatic cytosol were higher in hemorrhagic shock+GSS groups than those in hemorrhagic shock group, and the Rs of GR was the highest in hemorrhagic shock+10 mg/mL GSS group (P<0.01); Expression of GR mRNA in hepatic cytosol was higher in hemorrhagic shock+GSS groups than those in hemorrhagic shock group; The plasma concentrations of ACTH and GC were not altered by GSS. Conclusion GSS can alleviate the decrease of the Rs of GR in brain and hepatic cytosol through the way to accelerate the expression of GR mRNA. Perhaps the 10 mg/mL is the best dosage of ginsenosides.