Distribution of oxytocin receptor in adenomyosis and its relationship with dysmenorrhea

Objective To investigate the distribution of Oxytocin receptor (OTR) in eutopic and ectopic endometrium in adenomyosis,and to explore the relationship between OTR and dysmenorrhea.Methods Samples of eutopic endometrium of adenomyosis (n=28),adenomyotic lesion (n=28),normal endometrium (n=18) were collected. Expression of OTR in different tissue and cells during menstrual cycle was examined immunohistochemically.Results Adenomyotic lesion and eutopic endometrium showed more expression of OTR than in normal endometrium in adenomyosis (P0.05). The expressive rate of OTR in eutopic endometrium was higher at the proliferation stage than at the secretion stage,while less periodical variation of OTR expression was found in the ectopic lesion in adenomyosis. The expression of OTR in ectopic lesion with adenomyosis was higher in the group with severe dysmenorrhea than mild dysmenorrhea.Conclusions The strong expression of OTR in ectopic and eutopic endometrium may be associated with the development and growth of adenomyosis. The relationship between OTR and dysmenorrhea suggests an involvement of the OTR system in developing pelvic pain and/or dysmenorrhea.