Oxytocinergic regulation in pathogenesis of pelvic pain caused by adenomyosis

Objective: The aim of the study was to expand the understanding of pathogenesis of adenomyosis-associated pelvic pain. Material and Methods: We studied 30 (n = 30) biopsy samples obtained after hysterectomy in women with diffuse adenomyosis of grade II-III, accompanied by severe pain syndrome, who did not receive hormonal therapy. The morphologic comparison group comprised 30 (n = 30) biopsy samples obtained from women with adenomyosis, without pain syndrome, operated on for abnormal uterine bleeding, who also did not receive hormone therapy. Results: The total density of immunological OTR labeling in the adenomyotic lesion foci was 73.7 ± 1.8%, and in the morphological control group it was 35.2 ± 1.4% (p <0.05), which indicates a significant effect of oxytocin as a ureterotonic peptide. Processes of local neurogenesis and growth of nerve fibers was established due to an increase in the expression of the nervous system growth factor NGF in the myometrium stroma, in comparison with biopsy samples of morphological control. Conclusion: Pelvic pain pathogenesis in women with diffuse adenomyosis compared with the painless form of the disease is an increase in the activity of ureterotonic factors of OTR oxytocin. Compared to the painless form of adenomyosis, the myometrial innervation apparatus of patients with pelvic pain is characterized by a significantly higher expression of nerve growth factor. © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of the UR MED GRUPP (LLC).