目的:建立来曲唑诱导的多囊卵巢综合征(PCOS)动物模型,观察Cx43和Cx37在PCOS大鼠卵巢中的表达变化,探讨PCOS的发病机制。方法:①选择6周龄SD清洁级雌性大鼠60只,随机分为实验组、实验对照组、空白对照组,每组各20只。应用来曲唑灌胃制备PCOS大鼠模型,观察3组大鼠双侧卵巢及子宫大体解剖及组织学改变。②放射免疫法测定血清LH、FSH、E2、P、T水平。③免疫组化法观察卵巢组织中Cx43和Cx37的表达变化。结果:①动情周期:实验组大鼠失去规律性动情周期变化,提示无排卵。②器官重量:卵巢重量实验组显著高于实验对照组及空白对照组,差异有统计学意义(P<0.05);子宫重量实验组显著低于实验对照组及空白对照组,差异有统计学意义(P<0.05)。③卵巢组织学检查:实验组早期发育的小卵泡及闭锁卵泡,囊状扩张卵泡明显增加,颗粒细胞层数减少至2～3层,卵泡内卵母细胞或放射冠消失,黄体数量明显下降并伴有不完全的黄素化,而对照组镜下见多个黄体及不同发育阶段的卵泡,有排卵表现。④血清性激素水平:实验组血清T、LH、FSH浓度显著高于实验对照组及空白对照组(P<0.05),血清E2、P实验组浓度显著低于实验对照组及空白对照组(P<0.05)。⑤卵巢的颗粒细胞中Cx43的表达水平实验组显著低于实验对照组及空白对照组(P<0.05),卵母细胞与颗粒细胞间Cx37的表达水平实验组显著低于实验对照组及空白对照组(P<0.05)。结论:①来曲唑诱导的大鼠模型是理想的PCOS动物模型。②Cx43和Cx37在实验组卵巢中表达下调,与PCOS的发病密切相关。 OBJECTIVE: To establish animal model of polycystic ovary syndrome (PCOS) induced by letrozole and observe the expression changes of Cx43 and Cx37 in the ovary of PCOS rats and to explore the pathogenesis of PCOS. Methods: Sixty SD rats of 6 weeks old were randomly divided into experimental group, experimental control group and blank control group, with 20 rats in each group. Application of letrozole gavage PCOS rat model was established, the bilateral ovaries and the uterus of the three groups were observed gross anatomy and histological changes. ② The levels of serum LH, FSH, E2, P and T were measured by radioimmunoassay. ③ immunohistochemistry observed ovarian tissue Cx43 and Cx37 expression changes. Results: (1) Estrous cycle: The rats in the experimental group lost their regular estrous cycles, suggesting no ovulation. The weight of the organ in the experimental group was significantly higher than that in the experimental group and the blank control group (P <0.05), and the weight in the experimental group was significantly lower than that in the experimental group and the blank control group (P <0.05). ③ ovarian histological examination: experimental group early development of small follicles and atresia follicles, cystic dilated follicles increased significantly, the number of granulosa cells reduced to 2 to 3 layers, follicular oocytes or coronal disappearance of corpus luteum, the number decreased significantly Accompanied by incomplete luteinization, while in the control group see multiple corpus luteum and follicles at different stages of development, ovulation performance. Serum levels of sex hormones: The levels of serum T, LH and FSH in experimental group were significantly higher than those in experimental group and blank control group (P <0.05), and the concentrations of serum E2 and P in experimental group were significantly lower than those in experimental group and blank control group (P < 0.05). (5) The expression level of Cx43 in ovarian granulosa cells in experimental group was significantly lower than that in experimental group and blank control group (P <0.05). The expression level of Cx37 in oocyte and granular cell in experimental group was significantly lower than that in experimental control group and blank control group Group (P <0.05). Conclusion: Letrozole-induced rat model is an ideal PCOS animal model. The expression of Cx43 and Cx37 in the ovary of the experimental group was down-regulated, which was closely related to the pathogenesis of PCOS.