Objective: To determine whether endometrial expression of endothelial nitric oxide synthase (eNOS) or inducible NOS (iNOS) protein in women with endometriosis-associated infertility is different from that in the fertile controls, whether GnRH agonist (GnRH-a) regulates the endometrial expression of NOS in women with endometriosis-associated infertility, and whether there is a correlation between serum E2 or P levels, and the endometrial expression of eNOS or iNOS.
Design: Prospective controlled study.
Setting: University hospital for reproductive medicine and gynecologic endocrinology.
Patient(s): Thirty patients with endometriosis-associated infertility and 19 patients with carcinoma in situ of the cervix.
Intervention(s): Endometrial biopsy specimens and blood samples.
Main outcome measure(s): Endometrial eNOS and iNOS protein relative levels and serum concentrations of E2 or P.
Result(s): By Western blot analysis, iNOS was not detected, and a unique menstrual cycle-dependent expression of eNOS was observed. Eutopic endometrium in women with endometriosis-associated infertility before GnRH-a treatment showed higher levels of eNOS than that of the control group. After 3 months of GnRH-a therapy, eNOS levels in the endometrium were reduced. In addition, a significant positive correlation was found between serum E2 or P concentrations, and the endometrial expression of eNOS.
Conclusion(s): The GnRH-a treatment attenuated the endometrial expression of eNOS in women with endometriosis-associated infertility. Endogenous ovarian steroids influence endometrial eNOS expression.