Oxytocin mRNA content in the endometrium of non-pregnant women

Abstract

Objective: To study oxytocin mRNA in the human endometrium at different phases of the menstrual cycle.

Design: An exploratory study in non-pregnant women.

Setting: The Department of Obstetrics and Gynecology, Lund University Hospital, Sweden.

Participants: Thirty-three women of fertile age undergoing hysterectomy or endometrial curettage on routine benign gynaecologic indications.

Methods: Endometrial tissue was obtained throughout the menstrual cycle. The presence of oxytocin mRNA was investigated by in situ hybridisation and by real time PCR.

Main outcome measures: Oxytocin mRNA signalling intensity found by in situ hybridisation of tissue obtained at different times of the menstrual cycle. Relative amounts of oxytocin mRNA measured by real time PCR.

Results: The signal for oxytocin mRNA obtained by in situ hybridisation was more pronounced in glandular epithelial cells than in stromal cells. Furthermore, it was most marked around mid-cycle. The expression of oxytocin mRNA was confirmed by real time PCR.

Conclusions: The results indicate that oxytocin may be synthesised in the endometrium of non-pregnant women, particularly in the glandular epithelial cells. Hormone released from these sources may have a paracrine action on the uterus. Oxytocin mRNA expression seems to be ovarian hormone dependent with the highest concentration around mid-cycle.