六味地黄汤对快速老化模型小鼠下丘脑-垂体-卵巢轴的调节作用及机理研究

目的 研究快速老化模型小鼠(senescence accelerated mice，SAM)增龄过程中下丘脑一垂体一卵巢(HPO)轴功能的变化及六味地黄汤(LW)的调节作用。方法采用阴道涂片法确定动物的动情周期；放射免疫分析法检测血清雌二醇(E2)水平及下丘脑β-内啡肽(β-EP)和P物质(SP)含量；蛋白免疫印迹法(westemb lotting法)检测垂体促黄体生成素(LH)、垂体及卵巢雌激素受体a(ERa)水平。结果在增龄过程中SAM快速老化亚系SAM-prone／8(SAMP8)的动情周期和动情间期均较同龄抗快速老化系SAM-resis-tance／1(SAMRl)明显延长，血清E2水平显著降低、垂体LH水平显著升高，下丘脑β-EP含量随增龄逐渐下降，SP含量一过性升高后又下降，卵巢ERa表达量明显低下。LW能显著缩短SAMP8动情间期，增加卵巢重量，升高血清E2水平，明显降低垂体LH水平；并能升高下丘脑β-EP含量，提高卵巢ERa的表达量，但却明显降低下丘脑SP含量。口服雌激素能显著提高SAMP8血清E2水平，降低垂体LH水平，升高下丘脑β-EP及SP含量，并增加垂体ERa表达量，但明显降低卵巢重量及ERa水平。结论SAMP8在衰老过程中所表现的进行性HPO轴功能紊乱与下丘脑肽类神经递质含量及卵巢ERa水平的变化具有密切关系。LW对SAMP8 HPO轴功能紊乱具有改善或调节作用。

Study on Effect and Mechanism of Liuwei Dihuang Decoction in Modulating Hypothalamus-Pituitary-Ovary Axis in Senesc ence Accelerated Mice Model

OBJECTIVE: To study the changes of hypothalamus-pituitary-ovary (HPO) axis of senescence accelerated mice (SAM) model in their aging process and the modulatory effect of Liuwei Dihuang decoction (LW) on the changes. METHODS: Using vaginal smear to test the estrous cycle of animal; using radioimmunoassay to determine serum levels of estradiol (E2), and beta-endorphin (beta-EP) and substance P (SP) in hypothalamus; and the western bloting technique was adopted to quantify the level of luteinizing hormone (LH) in pituitary and estradiol receptor alpha (ER alpha) in pituitary and ovary. RESULTS: The estrous cycle and diestrus were significantly prolonged as SAMP8 aged, the concentration of serum E2 was lower, pituitary LH was higher in the SAMP8 than those in SAMR1. Content of beta-Ep and SP in hypothalamus gradually lowered during aging, SP content lowered after a transient increasing, and ER alpha expression lowered significantly. LW could significantly shorten the diestrus, increase weight of ovary, elevate serum E2 level, significantly reduce the LH level in pituitary, increase beta-EP content in hypothalamus and ER alpha expression in ovary, but significantly lower SP content in hypothalamus. Oral administration of estrogen could increase serum E2, beta-EP and SP content in hypothalamus and ER alpha expression in pituitary, but lower LH level in pituitary, weight of ovary and ER alpha level in ovary. CONCLUSION: SAMP8, in the aging process, develops a progressive HPO axis functional disturbance, it is closely related with the change of levels of peptide neuro-mediator in hypothalamus and change of ER alpha level in ovary. LW could improve or modulate the HPO axis functional disturbance in SAMP8.