中文摘要：

目的：研究肥胖与能量限制（CR）对大鼠卵泡发育和卵巢寿命的影响及其作用机制。方法：雌性SD大鼠随机分为对照（NC）组（自由取食）、高脂（HF）组（自由取食添加20%猪油的标准饲料）、CR组（摄食NC组70%的饲料）,每周测重,每天检测进食量和阴道涂片观察大鼠动情周期;苏木精-伊红染色观察卵泡发育和各级卵泡计数,Western blot检测SIRT1和其下游靶分子FOXO3a蛋白表达水平。结果：HF组体质量、内脏脂肪和卵巢质量均高于NC和CR组（P〈0.05）。HF组存活卵泡总数与NC组比无统计学意义,但原始卵泡数（22.1±0.7）及比例（10.3%±0.2%）相对于NC组（43.6±0.6,23.0%±0.2%）显著减少（P〈0.05）,而发育卵泡数（106.8±2.5 vs 81.0±1.8;P〈0.01）、闭锁卵泡数（79.2±0.9 vs 63.6±1.0;P〈0.01）和黄体数（36.1±1.4 vs 20.5±1.8;P〈0.05）均增多。CR组存活卵泡总数（138.9±1.2）、黄体数（28.6±1.5）和原始卵泡数（62.8±1.4）及比例（32.7%±0.4%）均显著增加,闭锁卵泡数（53.2±0.9）及比例（27.4%±0.3%）均减少。Western blot结果显示HF组卵巢SIRT1和FOXO3a蛋白表达低于NC组（P〈0.05）,而CR组SIRT1和FOXO3a表达高于NC组（P〈0.05）。结论：肥胖可能通过抑制SIRT1信号加速卵巢卵泡的发育与消耗,从而导致卵巢早衰;相反CR可能通过激活SIRT1信号抑制原始卵泡的发育启动以及各级卵泡的发育与闭锁,保持卵巢中卵泡的储备量,以此延长卵巢寿命。

英文摘要：

Objective： To investigate the effects of obesity and calorie restriction（CR）on the ovarian follicle development and ovary lifespan,and mechanisms involved.Methods： Adult female SD rats were randomly divided into the normal control（NC）group（fed ad libitum）,the high-fat diet（HF）group（fed ad libitum a rodent chow containing 20% lard）and the CR group（fed 70% of the food intake from the NC group）.The body weight gain,food intake,ovarian weight and visceral fat were recorded.The histological analysis of rat ovaries was performed and the numbers of ovarian follicles at each stage were counted.The expression levels of SIRT1 and its target FOXO3a proteins were examined by Western blot.Results： The rats in the HF group became moderately obese after 18 weeks.The body weight,ovary weight and visceral fat in the HF group were significantly higher than those in the NC and CR groups.The number of total surviving follicles of the HF group was comparable to that of the NC group,but the number and persentage of primordial follicles（22.1±0.7,10.3%±0.2%）were less than those of the NC group（43.6±0.6,23.0%±0.2%,P0.05）.The numbers of developing follicles（106.8±2.5 vs 81.0±1.8;P0.01）,atretic follices（79.2±0.9 vs 63.6±1.0;P0.01）and corpora lutea（36.1±1.4 vs 20.5±1.8;P0.05）significantly increased compared to the NC group.The numbers of total surviving follicles（138.9±1.2）,corpora lutea（28.6±1.5）and primordial follicles（62.8±1.4）,and the percentage of primordial follicles（32.7%±0.4%）in the CR group significantly increased,while the number and percentage of atretic follicles（53.2±0.9,27.4%±0.3%）decreased compared to the NC group.The results of Western blot showed that the expression of SIRT1 and FOXO3a proteins was significantly less in the ovaries of HF group than in the NC group.In contrast,the expression of the two proteins was siginicantly higher in the CR group than in the NC group.Conclusion： Our results suggest that obesity may accelerate the foll