Oestrogen and progesterone receptor expression in the female lower urinary tract, with reference to oestrogen status.

OBJECTIVE: To assess the incidence and distribution of both oestrogen and progesterone receptors throughout the female lower urinary tract, and to compare receptor expression in women of varying oestrogen status. PATIENTS AND METHODS: The study included 90 women undergoing surgery for urogynaecological conditions; 33 were premenopausal, 26 postmenopausal and taking no oestrogen supplementation, and 31 postmenopausal and receiving some form of hormone-replacement therapy. Biopsies were taken during surgery from the bladder dome, trigone, proximal urethra, distal urethra, vagina and vesicovaginal fascia in the region of the bladder neck. All biopsies were routinely fixed and processed for histopathological assessment, and were then labelled immunohistochemically with monoclonal antibodies directed against human oestrogen (NCL-ERLH2) and progesterone (NCL-PGR) receptors. Both oestrogen and progesterone receptor expression were assessed in the epithelial, subepithelial and muscle/deeper fascial regions of all tissue for overall tissue positivity for each receptor, and by semiquantitative analysis of receptor concentration using histochemical scoring of the tissues.
RESULTS: Oestrogen receptors were consistently detected in the squamous epithelia and were consistently absent in the urothelial tissues of the lower urinary tract of all women irrespective of oestrogen status; there was no significant variation in histological score. Progesterone receptor expression was more variable, being mostly subepithelial, and significantly lower in postmenopausal women receiving no oestrogen replacement.
CONCLUSION: These findings confirm the female lower urinary tract to be a target organ for the action of oestrogen and progesterone, and shed further light on the areas of the lower urinary tract likely to respond to hormone-replacement therapy. This may have implications for the use of oestrogen supplementation in the treatment of lower urinary tract disorders of postmenopausal women.