Objective:To investigate the possible reasons for low rate of implantation in rats with polycystic ovarian syndrome (PCOS) and the influence mechanism of dydrogesterone on implantation rate of PCOS rats. Methods:From the 80th day after birth, normal rats were given normal saline (NS) and PCOS rats model were given clomiphene (CC) for five consecutive days. Then they were mated with male rats. The pregnant rats were selected and divided into three groups with 6 in each group:group A (normal pregnant rats); group B (PCOS pregnant rats); group C (PCOS pregnant rats with dydrogesterone).On the 5th day of pregnancy, the levels of E2, P and TNF-α in each group were determined by ELISA, and the expression levels of progesterone receptor (PR) and intercellular adhesion molecule-1(ICAM-1) in endometrium were detected by immunohistochemistry. Results:In planting window period, the levels of E2 and TNF-α in group B and C were higher than those in group A (P<0.05, P<0.01);the levels of P in group A and C were higher than those in group B (P<0.05, P<0.01). The values of E2/P in the three groups were significantly different (P<0.05, P<0.01).The expression of PR in group B was lower than that in group A (P<0.05), and ICAM-1 expression levels in group B were lower than those in group A and C (P<0.05). PR expression had no correlation with E2, P and E2/P (P>0.05).ICAM-1 was positively correlated with P, while TNF-α was negatively correlated with E2/P. Conclusion:Low rate of implantation in PCOS pregnant rats was probably associated with abnormal sex hormone levels, TNF-α and decreased expression of PR and ICAM-1.Dydrogesterone can possibly improve the rate of implantation through adjusting P and E2/P, upregulating ICAM-1 and PR expression, and improving ovarian function and the receptivity of endometrium. |