下丘脑-垂体-性腺轴阻断对淫羊藿促性激素作用的影响

目的:淫羊藿对生殖系统的影响是其主要药理作用之一,也是其临床疗效的重要基础,但相应作用机制尚不明确。鉴于此,本研究拟探讨下丘脑-垂体-性腺轴(hypothalamus-pituitary-gonadal axis,HPGA)上游在淫羊藿总黄酮(total fla-vonoids of epimedium,TFE)提高雌二醇(estradiol,E2)水平及刺激附性器官增长中的作用及重要程度。方法:通过耳道吸出手术制备去垂体大鼠以形成HPGA阻断,将其与正常大鼠同时按400,200,100 mg.kg-1ig给予TFE 20 d,检测动物下丘脑促性腺激素释放激素(gonadotropin-releasing hormone,GnRH)、血清E2及促卵泡生成素水平,并计算子宫、卵巢脏器系数。结果:TFE 400mg.kg-1 ig给予可提高正常及去垂体大鼠子宫脏器系数、下丘脑GnRH水平,对血清E2水平亦有一定提高,但未达统计学显著水平;较小剂量则仅对正常大鼠显示类似作用。表明较大剂量TFE对去垂体所致HPGA阻断大鼠仍表现一定促性激素作用,但与对正常动物的作用相比较弱。结论:HPGA和下丘脑是淫羊藿促性激素作用的重要途径和靶器官。

Influence of Hypothalamus-pituitary-gonadal Axis Blocking on Sex Hormone Secretion Promoted by Epimedii Folium

Objective: The effect on reproductive system is one of the main pharmacological actions of Epimedii Foliun,and also the important basis for the clinical efficacy of Epimedium Folium,but the related mechanism remains unclear.Therefore,the role of upstream of hypothalamus-pituitary-gonadal axis(HPGA)on total flavonoids of Epimedium(TFE)stimulating the estradiol(E₂)level and the growth of accessorysexorgans would be studied in this research. Method: Model rats with blocked HPGA were prepared via Hypophysectomizing,and were administered by gavage with TFE at 400,200, 100 mg ·kg^-1 for 20 days,at the same time,three groups of normal rats were also administrated with the same doses.The level of gonadotropin-releasing hormone(GnRH),E₂ and follicle-stimulating hormone(FSH)was determined,as well as the organic index of uterine and ovary. Result: TFE 400 mg ·kg^-1 showed effect on increasing organic index and GnRH,E₂ level of both hypophysectomized and normal rats; the smaller dose behaved similar on normal animals.The results indicated that the larger dose still kept effect even on HPGA blocking rats,but the degree of influence was weaker than on normal rats. Conclusion: HPGA and hypothalamus play important role for Epimedi Folium to promote the sex hormone secretion.