美替拉酮阻断下丘脑-垂体-肾上腺皮质轴及加味逍遥丸对慢性心理应激小鼠免疫系统的影响

目的探讨美替拉酮阻断下丘脑-垂体-肾上腺皮质轴(hypothalamic-pituitary-adrenalcortexaxis,HPAA)对慢性心理应激小鼠免疫器官和细胞免疫功能有无保护作用,以及加味逍遥丸调节慢性心理应激损伤的作用是否与下丘脑-垂体-肾上腺皮质轴相关。方法将小鼠随机分为生理盐水对照组、加味逍遥丸对照组、美替拉酮对照组、美替拉酮合用加味逍遥丸对照组、生理盐水应激组、加味逍遥丸应激组、美替拉酮应激组、美替拉酮合用加味逍遥丸应激组。其中对照组小鼠不予以应激刺激,应激组小鼠采用电刺激条件反射箱诱导建立慢性心理应激模型。检测各组小鼠体质量、血清糖皮质激素水平、胸腺指数、胸腺细胞凋亡率、脾脏自然杀伤细胞活性及淋巴细胞转化率,并观察小鼠胸腺组织病理学改变。结果各应激组与其相对应的非应激对照组比较,其胸腺指数明显下降,自然杀伤细胞活性及淋巴细胞转化率均明显下降;同时,胸腺细胞凋亡率升高,胸腺组织病理损伤加重。美替拉酮及加味逍遥丸应激组与生理盐水应激组比较,其血清糖皮质激素含量明显下降,自然杀伤细胞活性及脂多糖刺激的淋巴细胞转化率明显升高,胸腺组织病理损伤减轻。美替拉酮合用加味逍遥丸应激组与单纯的美替拉酮或加味逍遥丸应激组各项指标比较,均无明显差异。结论阻断HPAA对慢性心理应激小鼠的免疫系统有明显的保护作用。加味逍遥丸对慢性心理应激小鼠的保护作用与美替拉酮阻断HPAA的效应基本一致,两者无叠加、协同效应。推测HPAA是加味逍遥丸抗应激损伤的作用靶点之一。

Effects of blockage of hypothalamic-pituitary-adrenal cortex axis by metyrapone and Jiawei Xiaoyao Pills on immune system in mice exposed to chronic emotional stress

Objective: To explore the effects of Jiawei Xiaoyao Pills (JWXYP) on immune system of mice exposed to chronic emotional stress, and to compare its effects with blockage of hypothalamic-pituitary- adrenal cortex axis (HPAA) by metyrapone. Methods: Eighty male mice were randomly divided into eight groups: normal saline-treated group, normal saline-treated stress group, JWXYP-treated group, JWXYP-treated stress group, metyrapone-treated group, metyrapone-treated stress group, metyrapone and JWXYP-treated group and metyrapone and JWXYP-treated stress group. A box of electrical shock was used to induce chronic emotional stress in mice. The metyrapone was applied to blocking the HPAA. The JWXYP, a classical formula of traditional Chinese medicine, which can alleviate the damages caused by chronic emotional stress, was also used to compare its effects with that of metyrapone. The body weight, thymus index, rate of apoptosis in thymus, serum concentration of glucocorticoid, activity of natural killer cells, lymphocyte transmission rate of mice were all measured and examined after interventions. The pathological changes of thymus tissue were observed. Results: The thymus index, activity of natural killer cells and lymphocyte transmission rate were lower while the rate of apoptosis in thymus as well as the severity degree of pathological damages in thymus tissue were increased in the different drug-treated stress groups as compared with those in the corresponding drug-treated groups without stress. The activity of natural killer cells and the lymphocyte transmission rate induced by lipopolysaccharide were increased while the serum concentration of glucocorticoid and the severity degree of pathological damages in thymus tissue were decreased in both the metyrapone-treated stress group and JWXYP-treated stress group as compared with those in the normal saline-treated stress group. The combined intervention of metyrapone and JWXYP did not show better effects on immune system in mice exposed to chronic emotional stress than single metyrapone or JWXYP interventon. Conclusion: Blockage of HPAA by metyrapone intervention shows a significant protective effect on immune system in mice exposed to chronic emotional stress, and the JWXYP also exerts a similar protective effect against damages induced by chronic emotional stress. The HPAA may be one of the action targets of protective effects of JWXYP.