Evidence of Progesterone Receptors in the Mucosa of the Urinary Bladder

Objective: To investigate whether progesterone receptors are present in the mucosa of the urinary bladder of continent premenopausal women compared with continent postmenopausal women. Materials and methods: Fifty-seven biopsies from the mucosa of the trigone and lateral wall of the urinary bladder were examined by the avidin-biotin-peroxidase immunohistochemical technique for the presence of estrogen and progesterone receptors. The specimens were obtained at cystoscopy performed to investigate hematuria in 42 patients and neoplasia in 15. The study group (n = 29) comprised non-pregnant premenopausal women in the luteal phase of their menstrual cycle and the control group (n = 28) comprised postmenopausal women. None of the subjects had urinary incontinence or was taking medication with hormones. In no case did the primary lesion involve the specimen used for laboratory analysis. Results: There was positive immunostaining with estrogen in 28 patients of the study group (96.5%) and 4 (14.4 %) in the control group (p < 0.0001). The 28 samples of the study group also showed positive immunostaining for progesterone receptors. There was positive immunostaining with progesterone in 18 samples (64.3%) of the control group (p < 0.01). Fourteen samples (50%) of the control group thus showed positive immunostaining for progesterone but no evidence of positive immunostaining with estrogen. Immunostaining for estrogen and progesterone receptors was similar in trigonal and lateral wall samples. Conclusion: In continent pre- and post-menopausal women, a direct progestogenic effect on the mucosa of the urinary bladder seems likely in addition to estrogen.