关键词: 控制性超促排卵, 大鼠模型, 孕马血清促性腺激素, 人绒毛膜促性腺激素

Abstract: Objective To select an ideal controlled ovarian hyperstimulation (COH) rat model that is in line with clinical practice, and provide a good experimental basis for the follow-up experiment. Methods Seventy-five rats were randomly divided into normal group ( N) , model 10 group ( M10 ) , model 20 group (M20) , model 40 group (M40) and model 100 group (M100) , with 15 rats in each group. Each model group was given intraperitoneal injection of 10 IU, 20 IU, 40 IU and 100 IU of pregnant horse serum gonadotropin ( PMSG) at 5:00 pm on the day after the estrus period. After 48 hours, the rats were given intraperitoneal injection of 10 IU, 20 IU, 40 IU and 100 IU of human chorionic gonadotropin ( HCG) , and immediately caged. The large number of sperm found on the vaginal smear the next day was recorded as the first day of pregnancy. On the next day, vaginal smear of seeing a large number of sperms was treat as the first day of pregnancy (D1) . On the D8 days, record the pregnancy rate and the number of implanted blastocysts. Another 25 rats were randomly divided into 5 groups as above. The rats in each group were mated and collected the samples on the D5 days. The expression of the pinopodes and the LIF protein expression were observed. Result There was no significant difference in the mating rate between the five groups ( P > 0. 05 ) . Compared with N group, the pregnancy rate of M10 group was not significantly lower ( P > 0. 05 ) , while the pregnancy rate of M20, M40 and M100 groups were significantly lower than that of N group (P<0. 01) . The number of blastocysts of M20, M40 and M100 groups was significantly increased than that of N group ( P < 0. 05 ) . Compared with N group, the endometrial expression of LIF protein in Day 5 of M10 group was not significantly lower (P>0. 05) ; the LIF protein in M20, M40 and M100 groups was significantly lower ( P<0. 05) ; the LIF protein in M40 group and M100 group was less than that in M20 group, but the difference was not statistically significant (P>0. 05) . The result of electron microscopy showed that there were abundant pinopodes in endometrial glandular epithelial cells of N group in Day 5, while the pinopodes was almost not expressed in the M20 group. Conclusion The pregnancy rate of rats in the M20 group was significantly lower than that in thenormal group, and the average number of blastocysts was higher, the pinocytosis appeared earlier, and the expression of LIF was lower than that in the normal group, which was an ideal model in line with clinical practice.

Key words: controlled ovarian hyperstimulation, rat model, pregnant mare serum gonadotropin, human chorionic gonadotropin