慢性轻度不可预见性应激雌性昆明小鼠模型在生殖医学领域应用的可行性探讨

Application of Chronic Unpredictable Mild Stress Female Kunming Mice Model in the Field of Reproductive Medicine

目的选用雌性昆明小鼠建立慢性轻度不可预见性应激(CUMS)动物模型,了解CUMS对雌性昆明小鼠生殖功能的影响,为后续探讨应激对生殖功能的影响机制提供适宜的动物模型。方法将240只雌性昆明小鼠以正常饲养5 d后,采用随机数字表法分为对照组(90只)和实验组(150只)。雄性小鼠(为合笼备用)、对照组小鼠均按正常条件饲养。将实验组150只雌性昆明小鼠以9种慢性、轻度和不可预见性应激因子在4周内随机应用造模。4周后,对两组小鼠采用旷场实验和糖水消耗实验,观察体质量变化,以进行有效性验证。对造模成功的CUMS小鼠进行孕马血清促进腺激素(PMSG)/人绒毛膜促性腺激素(HCG)促排卵,通过获取卵巢组织标本、卵母细胞、2-细胞期胚胎、孕4 d胚胎(囊胚、桑葚胚),并进行孕5 d体内着床位点实验,以观察卵巢反应及胚胎发育潜能。结果 4周CUMS刺激后,与对照组小鼠相比,实验组小鼠体质量增加、2%糖水消耗实验及旷场实验均存在明显差异(P<0.05)。PMSG/HCG促排治疗后,实验组小鼠卵巢的窦卵泡及排卵前卵泡较对照组明显减少(P<0.05);实验组小鼠的卵母细胞数、受精率、2-细胞胚胎数、孕4 d胚胎数、囊胚数、优胚率及孕5 d着床位点数均明显低于对照组,差异均有统计学意义(P<0.05)。结论 CUMS雌性昆明小鼠模型是一种生殖功能减退的情绪应激动物模型,具有有效性、可操作性和可重复性,可进一步用于生殖医学领域机制方面的研究。

Objective To explore the effect of chronic unpredictable mild stress（CUMS） on the reproductive function of mice and provide a suitable animal model for reproduction and stress. Methods A total of 240 female Kunming mice were feed for 5 days, and then divided randomly into the control group（n=90） and experimental group（n=150）. The mice in the experimental group were stressed by 9 chronic mild unpredictable stress factors for 4 weeks and validated by open field test and sucrose consumption test. We administrated pregnant mare serum gonadotropin（PMSG）/human chorionic gonadotropin（HCG） for induction of superovulation and observed the ovarian response and embryo development potential. Results After 4-week CUMS stimulation, the weight gain, 2% sugar consumption test and open field test were significantly different between the mice in two groups（P〈 0.05）. After PMSG/HCG was administrated, the antra follicles and preovulatory follicles significantly reduced significantly in the experiment group than that in the control group（P〈 0.05）; the number of oocytes, fertilization rate, 2-cell embryos, D4 embryos, blastocysts, high quality embryo rate and D5 bed points were all significantly decreased in the experiment group than those in the control group（P〈 0.05）. Conclusion The CUMS female Kunming mice model is a kind of emotional stress animal model with low reproductive function, which is effective, operable and repeatable; it could be used for further study on the mechanism of reproductive medicine.