The Effect Of Prolonged Gonadotropin Releasing Hormone Agonist Therapy On Expression Of Nitric Oxide Synthase In The Endometria In Women With Endometriosis And Infertility And Its Sex Hormone Regulation

Backgroud Endometriosis affects a significant number of women of reproductive age. A consensus has been reached on that stage III to IV endometriosis is often complicated by infertility. Prolonged use of GnRH agonist (GnRHa) after surgical treatment of stage III to IV endometriosis before IVF-ET in the treatment of endometriosis-related infertility resulted in significantly higher ongoing pregnancy rates than did standard controlled ovarian hyperstimulation regimens only. Although numerous mechanisms have been proposed to explain how endometriosis may interfere with normal reproduction and how endometriosis develop, to date there is no conclusive evidence as to how this disease affects fertility and what is exactly the pathogenesis of endometriosis. An understanding of mechanism by which endometriosis and it's intercurrent infertility are produced is indispensable for preventing and curing the disease. Optimal levels of nitric oxide (NO) and/or nitric oxide synthase (NOS) expression in the endometria are crucial for normal endometrial function, embryo implantation, embryonic development and pregnancy maintenance. However, there is no report on endometrial expression of endothelial NOS (eNOS) and inducible NOS (iNOS) in patients with stage III to IV endometriosis and infertility before and after GnRHa treatment. There is also no report on the correlation between expression levels of endometrial eNOS or iNOS and serum concentrations of estradiol (E2) or progesterone(P).Objective (1)To evaluate the different expression of endometrial NOS isoform [eNOS or iNOS] protein and mRNA levels between infertility women with stage III to IV endometnosis and fertile control women; (2)To investigate the effect of prolonged GnRHa on the endometrial expression of eNOS and iNOS in infertility women with stage III to IV endometnosis; (3)To compare the difference about serum E₂ or P levels among women with stage III to IV endometriosis and infertility before or after GnRHa therapies, and the fertile control women; (4)To examine the correlation between the endometrial expression of eNOS or iNOS and serum E₂ or P levels.Materials and Methods Patients with laparoscopically documented stage III to IV endometriosis according to r-ASRM criteria and infertility without (30 cases, endometriosis group) and with GnRHa treatment (18 cases, treatment group), and fertile patients with carcinoma in situ of the cervix (19 cases, control group) were recruited in the study scheme. Immunohistochemistry (IHC) were resorted to demonstrate the endometrial localization and semi-quantification of eNOS and iNOS; Western immunoblot assay were used to analyse eNOS protein and iNOS protein relative expression in the eutopic endometria; Reverse transcription polymerase chain reaction (RT-PCR) were used to screen eNOS mRNA and iNOS mRNA relative expression in the eutopic endometria; Using electrochemiluminescence immunoassay, serum E₂ and P concentrations were assayed.Results (1) the Localization of eNOS and iNOS in Endometria by IHC: eNOS was localized predominantly to the glandular epithelium, luminal epithelium and endometrial microvascular endothelium throughout the menstrual cycle, with weak staining of stroma cells; iNOS was only detectable weakly in occasional specimens (14 secretory stage endometria), was predominantly found in glandular epithelium and stromal cells. There was no staining of iNOS in endometrial microvascular endothelium. (2) Semi-quantification of eNOS by IHC: About the staining scores of endometrial eNOS in the glandular epithelium or in the luminal epithelium, endometriosis group displayed higher than control group, but a significant difference was found only in early, mid-proliferative phases and mid-, late-secretory phase(P<0.05); treatment group was lower than endometriosis group, but a significant difference was found only in early-, mid-proliferative phases and early-, mid-secretoryphase(P<0.05). About the staining scores of endometrial eNOS in the microvascular endothelium and stroma cells, endometriosis group were significantly h...