Immunoreactivity of oxytocin receptor and transient receptor potential vanilloid type 1 and its correlation with dysmenorrhea in adenomyosis

OBJECTIVE: We sought to investigate the expression and localization of oxytocin receptor (OTR) and transient receptor potential vanilloid type 1 (TRPV1) in women with and without adenomyosis. STUDY DESIGN: Ectopic and homologous eutopic endometrium from 50 women with adenomyosis and endometrium from 18 women without adenomyosis were used for immunohistochemical analysis of OTR and TRPV1. Microscopic evaluation assessed the presence and localization of OTR and TRPV1 throughout the menstrual cycle in both eutopic endometrial and endometriotic tissues of women with adenomyosis and compared them with normal endometrium. RESULTS: Compared with normal endometrium, immunoreactivity of OTR and TRPV1 were significantly increased in ectopic endometrium. Both OTR and TRPV1 immunoreactivity were positively correlated with the severity of dysmenorrhea and found to be significant predicators for dysmenorrhea severity. CONCLUSION: These findings suggest that OTR and TRPV1 may be involved in dysmenorrhea and its severity in adenomyosis and may be potential therapeutic targets.