Effect Of Kunling Pill On Endothelial Nitric Oxide Synthase Expression And Angiogenesis In Implantation Period In Patients With Repeated Implantation Failure

Objective: To study the effect of Kunling Pill on the endothelial nitric oxide synthase expression and angiogenesis in the endometrium of patients with repeated implantation failure(RIF),explore the relationship between eNOS expression and endometrial receptivity,and investigate the causes of RIF and the mechanism of Kunling Pill in improving endometrial receptivity in RIF patients.Methods: A total of 120 patients with repeated failure of frozen embryo implantation were included in our research as repeated implantation failure group.Among them,60 patients were assigned to the treatment group with oral intake of Kunling Pill and the rest without oral administration were assigned to the control group.Select the first transplant and pregnancy for the pregnancy group as a positive control.In the treatment group,the endometrial samples were first obtained 7 days after the ovulation in the preparatory cycle(pre-treatment group).Oral intake of Kunling Pills was started from the same day and lasted for two months.The endometrial samples were then obtained 7days after the ovulation in the second menstrual cycle(post-treatment group).In the control group and pregnancy group,the endometrial samples were only obtained 7 days after ovulation in the preparatory cycle.RT-PCR and immunohistochemistry were used to detect the expression of eNOS in the endometrium of the three groups.Endometrial microvessel density was detected by immunohistochemistry.Results: 1.There was no significant difference in age,infertility duration,BMI,baseline FSH,and baseline LH between trepeated implantation failure group and pregnancy group(P>0.05).2.There was no significant difference in age,infertility duration,BMI,baseline FSH,and baseline LH between thetreatment group and the control group(P>0.05).3.Comparing pregnancy group with repeated transplantation failure group,the mRNA expression of eNOS in pregnancy group(0.748±0.874 VS 0.293±0.105),e NOS protein expression and MVD count(15.860±4.519 VS 13.680±4.087)were significantly higher than those in the repeated transplantation failure group(P<0.05).4.There was no statistical difference bewtten control group and pre-treatment group in the expression of eNOS mRNA(0.285±0.098 VS0.300±0.112),eNOS protein expression and MVD count(14.017±4.253 VS13.350±3.922).5.The expression of eNOS mRNA(0.745±0.087 VS0.300±0.112),eNOS protein expression and MVD count(15.767±4.204 VS13.350±3.922)were significantly higher in the post-treatment group than in the pre-treatment group and the difference was statistically significant(P<0.05).6.Compared with the control group,the embryo implantation rate(43.20% VS 22.22%)and clinical pregnancy rate(53.33% VS 35.0%)of the treatment group were significantly higher in the treatment group,and the difference was statistically significant(P<0.05).There was no significant difference in the endometrial thickness(10.77±2.05 VS 10.95±2.19),the level of the transplanted embryo and the early abortion rate(15.60% VS 14.30%)between the two groups(P>0.05).7.Spearman rank correlation analysis indicated that eNOS protein expression was positively correlated with MVD count,and the difference was statistically significant(P<0.05).Conclusions: 1.The decreased eNOS expression during implantation can be one of the causes for RIF.Therefore increasing eNOS expression may provide an effective way to avoid repeated failure of transplantation.2.Increased implantation MVD in patients undergoing repeated implant failures may improve pregnancy outcomes,and MVD may be one of the predictors of clinical outcomes.3.Kunling Pill may increase endometrial receptivity and improve clinical outcome in RIF patients by enhancing eNOS expression and increasing MVD count during implantation.