LOCATION AND CONCENTRATION OF ESTROGEN, PROGESTERONE, AND ANDROGEN RECEPTORS IN THE BLADDER AND URETHRA OF THE RABBIT

The objective of this study was to determine location and concentratio n of estrogen, androgen, and progesterone receptors in the bladder and urethra of the rabbit. Two urethral and two bladder specimens were ob tained from four 12-week-old female New Zealand white rabbits. Rat mon oclonal antibody (AN1-15) to human androgen receptor and (H222) to hum an estrogen receptor and mouse monoclonal antibody (PR6) to chicken pr ogesterone receptor were used. Immunocytochemical staining was perform ed and specimens were evaluated for presence and location of steroid r eceptors. Androgen receptors were found in the highest concentrations in urethral and bladder epithelium. Low to low/moderate concentration were found in smooth muscle. Estrogen receptors were found in moderate to moderate/high concentrations in urethral epithelium and bladder an d urethral smooth muscle. Progesterone receptors were not found in app reciable concentrations from any location, though the animals were not pretreated with estrogen. The rabbit model suggests a mechanism by wh ich estrogen therapy can be effective in treating postmenopausal lower urinary tract symptoms. Progesterone receptors were not found in appr eciable concentrations, suggesting progesterone therapy may not dimini sh the effectiveness of estrogen therapy by acting on urethral progest erone receptors. The effect of androgens on the lower urinary tract ne eds further investigation to determine if androgen therapy can allevia te lower urinary tract symptoms. (C) 1995 Wiley-Liss, Inc.