Expressão da leptina e seus receptores no ovário humano normal e no acometido por endometrioma

Abstract

This study was designed to investigate leptin levels in the fluid in ovarian endometriomas and to compare the expression of leptin and its receptors in ovarian tissue affected by endometrioma in infertile women to its expression in the normal ovarian tissue of fertile controls without endometriosis. In this observational study, ovarian tissue, blood samples and peritoneal fluid were obtained from 20 women (10 fertile controls without endometriosis or any ovarian disease, who were undergoing tubal ligation surgery, and 10 infertile women with severe endometriosis and ovarian endometrioma). The ovarian endometriomal fluid was aspirated, and peritoneal-implant biopsies were performed. The tissues removed during the surgeries were immediately frozen in liquid nitrogen to determine expression levels by western blot and leptin levels by ELISA. The leptin receptor was expressed at higher levels in the ovarian tissue affected by endometrioma than in the normal ovarian tissue (control=0.38±0.05, study=0.60±0.09, p=0.03), but there was no significant difference in leptin levels between these groups (control=0.57±0.1, study=0.35±0.1, p=0.18). Positive and significant correlations were observed between leptin and its receptor in the ovarian endometrioma (r=0.85, p= 0.004) and in the peritoneal-implant (r=0.87, p= 0.001). ELISA results demonstrate a greater leptin concentration within the endometrioma fluid compared with the serum and the peritoneal fluid (serum=8.4±1.0, PF=1.6±0.5, EF=73.8±16.2, p=0.0001), but there was no correlation between these variables. A positive, significant and strong correlation was observed between peritoneal fluid leptin levels and the expression of leptin and its receptor in peritoneal-implant (leptin: r=0.88, p=0.0008; OBR: r=0.96, p=0.0001) and between the endometrioma fluid leptin levels and the expression of leptin and its receptor in the ovarian endometrioma (leptin: r=0.94, p=0.001; OBR: r=0.84, p=0.02). These data suggest that leptin may play an important role in the physiopathology of ovarian endometrioma through a modulatory interaction with its active receptor.