The expression of oxytocin receptor in uterine junctional zone of women with endometriosis

Objective To explore the expression and clinical significance of oxytocin receptor (OTR) in the junctional zone (JZ) in women with endometriosis (EMS). Methods Forty-three patients with EMS (including 25 cases in proliferative phase and 18 cases in secretory phase) undergoing hysterectomy were selected as EMS group. The tissues of uterine JZ were obtained. In the meantime, 54 patients (including 28 cases in proliferative phase and 26 cases in secretory phase) with cervical carcinoma, ovarian cancer or cervical intraepithelial neoplasia were selected as control group. Immunohistochemistry technique was used to detect the protein expression of OTR in the uterine JZ with and without EMS. Results In control group, the OTR expression of the uterine junctional in proliferative group was 0.156±0.056, which was significantly higher than that of secretory phase (0.126±0.030) (P=0.017). In EMS group, the difference of the OTR expression of the uterine JZ between the proliferative phase (0.205±0.106) and secretory phase (0.187±0.070) had no statistical significance (P=0.523). The expressions of OTR in the uterine JZ of proliferative phase of EMS group and control group (0.156±0.056) showed a significant difference (P=0.043). Similarly, the OTR expression in the uterine JZ of secretory phase was significantly higher than that (0.126±0.030) of control group (P=0.002). The expression level of OTR in the uterine JZ of women with EMS is positively correlated with the degree of dysmenorrhea (r=0.836, P<0.05). Conclusion The higher expression of OTR in the uterine JZ of EMS might be associated with pathogenesis and related symptoms of EMS. Key words: Endometriosis (EMS); Oxytocin receptor (OTR); Uterine junctional zone