能量限制下SIRT1高表达对大鼠卵巢生殖寿命的影响

Effect of calorie restriction on expression of SIRT1 and reproductive lifespan of female rats

目的观察能量限制后成年大鼠卵巢SIRT1高表达对卵巢功能和寿命的影响。方法 24只10周龄雌性SD大鼠,随机分为35%能量限制组和对照组。对照组不给予特殊处理自由取食,能量限制组予对照组食量的65%,每日调整饲料量,每周称体重。HE染色卵巢组织形态学观察及卵泡分类计数,免疫组织化学法观察SIRT1蛋白定位,Western blot检测SIRT1蛋白表达。结果能量限制组大鼠摄入能量少,体重的增长速度要低于对照组(P<0.05),腹部脂肪明显少于对照组(P<0.01);卵巢外观形态与对照组无异,原始卵泡数明显多于对照组(P<0.01),窦状卵泡少于对照组(P<0.01);SIRT1蛋白表达定位于卵母细胞的胞核,弱表达于胞浆,免疫印迹检测显示能量限制诱导大鼠卵巢组织SIRT1高表达,灰度值扫描与对照组有显著性差异(P<0.05)。结论内源性SIRT1高表达可能是抑制原始卵泡的转化和发育,能量限制诱导SIRT1高表达可能对于延长卵巢的生殖寿命及提高卵巢的储备有积极作用。

Objective：To investigate the effect of calorie restriction on expression of SIRT1 and extension of ovarian reproductive life in rat.Methods：Twenty four female SD rats of 10 weeks old were randomized into two groups：12 rats in the normal control group with fed standard rodent chow ad libitum（NC group）,and 12 rats in the calorie restriction group with fed 65% food of NC group（CR group）.The food intake was daily recorded,and the food supply of the CR group was adjusted accordingly.The body mass was monitored weekly.The ovarian tissue sections were stained with hematoxylin-eosin.Follicles were counted and classified as primordial follicle,primary follicle,secondary follicle,antral follicle,corpora atretica.Immunohistochemical staining method was used to detect the expression and localization of SIRT1.Western-blot methods were used to detect the expression of SIRT1 in rat ovary.Results：The NC rats were fatter than the CR rats.There was a significant increase in the total number of primordial follicles（P〈 0.01） and a decrease in the number of antral follicles （P 〈0.01） in CR rats compared with NC rats.Immunohistochemical analysis revealed that SIRT1 was localized in the nucleus and weakly expressed in the cytoplasm of oocytes from primordial follicles to antral follicles.SIRT1 expression in CR group was significantly higher than that in NC group（P〈0.05）.Conclusions：Calorie restriction up-regulates the expression of SIRT1 and may inhibit the mature of primordial.High expression of SIRT1 may protect ovarian follicular reserves,which may be prolong the reproductive life of ovary.