Abstract：
The effect of the insulin-sensitizing drug metformin on preovulatory follicle (POF) number, ovulation rate, fetal rate and prolificacy was studied in forty-six cyclic Malpura ewes. After estrus synchronization, the ewes were equally divided into two groups (n = 23). The treatment group (MET) received a daily oral dose of metformin at a rate of 500 mg/animal for approximately 12 weeks, spanning five estrous cycles, as against untreated control (CON). All the ewes were bred to proven rams at the end of treatment. Ovarian ultrasound scans were performed at each estrus and day 9 of each cycle to assess the number and diameter of POFs and corpora lutea (CL), respectively. A comprehensive assessment of circulating hormones including, estradiol, progesterone, androstenedione, and insulin as well as metabolic indicators such as glucose, and lipid profile parameters was performed. At the end of treatment on the day of estrus (E5D0), the treatment showed a stimulatory effect on follicular development with a 53.2% (P < 0.001) increase in the number of POFs. It also increased the ovulation rate by 67.4% (P < 0.01), with a higher proportion (χ2df1 = 10.7, P < 0.001) of ewes in the MET group having multiple ovulations compared to the CON group (82.6 vs. 30.4%). With 1.48 ± 0.12 prolificacy rate in MET ewes, the proportion of ewes giving birth to multiple lambs was 2.9-fold higher than in the CON group. Plasma estradiol, insulin, glucose, total cholesterol, and LDL-cholesterol concentrations were lower (P < 0.05) in the MET ewes than in the CON. The results of the present study indicate that metformin can increase the number of POF, ovulation rate, fetal rate and prolificacy in ewes, while reducing the plasma estradiol, insulin, glucose and cholesterol in MET ewes.
摘要：
胰岛素增敏药物二甲双胍对排卵前卵泡（POF）数量的影响，排卵率,在46只周期性马普拉母羊中研究了胎儿率和繁殖力。发情同步后，母羊平均分为两组(n=23)。治疗组（MET）接受每日口服剂量的二甲双胍，剂量为500mg/动物，持续约12周，跨越五个发情周期，相对于未处理的对照(CON)。在治疗结束时，所有的母羊都被培育成经过验证的公羊。在每个发情期和每个周期的第9天进行卵巢超声扫描，以评估POF和黄体（CL）的数量和直径，分别。对循环激素的全面评估，包括，雌二醇,黄体酮,雄烯二酮,和胰岛素以及葡萄糖等代谢指标，和脂质分布参数进行。在发情期当天（E5D0）的治疗结束时，治疗对卵泡发育有刺激作用,POFs数量增加53.2%(P<0.001).排卵率提高67.4%(P<0.01),与CON组相比，MET组具有多个排卵的母羊比例更高（χ2df1=10.7，P<0.001）（82.6vs.30.4%）。MET母羊的繁殖率为1.48±0.12，产下多只羔羊的母羊比例比CON组高2.9倍。血浆雌二醇，胰岛素，葡萄糖，总胆固醇,MET母羊的LDL-胆固醇浓度低于CON（P<0.05）。本研究的结果表明，二甲双胍可以增加POF的数量，排卵率,母羊的胎儿率和繁殖力，同时减少血浆雌二醇，胰岛素，MET母羊的葡萄糖和胆固醇。
