淫羊藿甙对大鼠早期卵巢卵泡发育和卵母细胞凋亡影响的初步研究

Primary study on the effect of icariine on early ovarian follicle development and oocyte apoptosis in rat

目的探讨淫羊藿甙对早期卵泡发育和卵母细胞凋亡的影响。方法用淫羊藿甙对受孕11.5d大鼠灌胃[100mg/(kg·d)]直至生产,分别取淫羊藿甙灌胃组(试验组)和空白对照组中出生2d、4d、8d龄新生大鼠卵巢,用苏木素-伊红(hematoxylin-eoxin,HE)染色观察不同发育阶段卵泡比例,TUNEL(TdT-mediateddUTPNick-End Labeling)荧光染色检测卵巢内卵母细胞凋亡变化,免疫组化染色观测caspase-3的定位和表达水平。结果在试验组新生大鼠,2d龄卵巢卵母细胞巢内卵母细胞比例增高,原始卵泡比例下降;4d龄卵巢中原始卵泡比例显著增高,发育卵泡比例降低;8d龄卵巢各不同发育阶段卵泡比例与对照组相一致;试验组2d卵巢内TUNEL阳性率降低;Caspase-3主要在卵母细胞巢和原始卵泡的卵母细胞中表达,2d卵巢表达水平高于4d卵巢。结论淫羊藿甙能延缓新生大鼠卵母细胞巢破裂,抑制原始卵泡的发育启动,减少卵泡的消耗;能降低2d龄卵巢卵母细胞的凋亡率,抑制卵母细胞凋亡,增加原始卵泡池的储备量。

[Objective] To study the effect of icariine on early ovarian follicle development and oocyte apoptosis in rat. [Method] Pregnant rats were treated with icariine by intragastric administration on day 11.5 after gestation till delivery. Ovaries were collected from the postnatal rats of both experiment group and control group on day 2, 4, and 8 after birth. The ratio of different developmental ovarian follicles stages was examined by hematoxylin-eoxin staining. The oocyte apoptotic profiles were determined by terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling （TUNEL） fluorescence staining, the protein expression of caspase-3 was detected by immunohistochemistry. [Result] The ratio of oocytes in oocyte nest raised and primordial follicle decreased in the 2-day-old rats＇ ovaries of experiment group. The ratio of primordial follicles in the 4-day-old rats＇ ovaries of experiment group was significantly increased, while the ratio of developmental follicles decreased. There was no effect of icariine on all ovarian follicle stages in ovaries on day 8 . The apoptotie rate of TUNEL in the experiment group ovaries decreased. The expression of caspase-3 was mostly seen in oocyte nest and oocyte of primordial follicle. The rate of caspase-3 positive oocytes in ovaries on day 2 was more than that of ovaries on day 4. [Conclusion] Icariine can postpone oocyte nest breakdown, inhibit primordial follicle development and reduce ovarian follicle loss. Icariine can also decrease oocyte apoptotic rate, attenuate oocyte cell death and increase the reserve of primordial follicle pool.