THE URINARY-BLADDER OF A WOMAN IS A NOVEL SITE OF LUTEINIZING-HORMONEHUMAN CHORIONIC-GONADOTROPIN RECEPTOR GENE-EXPRESSION

OBJECTIVE: The female reproductive tract contains functional luteinizi ng hormone-human gonadotropin receptors; therefore our objective was t o test the hypothesis that bladder trigone, which is derived from inte rmediate mesoderm along the urogenital ridge during embryonic developm ent of the female reproductive tract, may also contain these receptors . STUDY DESIGN: Bladder trigones or domes were biopsied from 15 premen opausal and 19 postmenopausal women undergoing surgical correction of genital prolapse, incontinence, or both. The biopsy specimens were sub mitted for luteinizing hormone-human chorionic gonadotropin receptor a nalysis by in situ hybridization and immunocytochemical examination. T he receptor immunostaining was visually scored by 3 investigators with out knowing the identity of the menopausal status.RESULTS: In situ hyb ridization demonstrated the presence of receptor transcripts, and immu nocytochemical examination revealed the presence of receptor protein i n bladder trigone. The bladder trigones from postmenopausal women cont ained lower levels compared with those from premenopausal women, imply ing that luteinizing hormone might down-regulate its own receptors. Tr ansitional epithelium contained the highest receptor levels followed b y smooth muscle and blood vessels. The bladder dome contained receptor levels similar to those in trigone, which suggests that a common embr yologic origin is not the only reason for bladder trigone containing t he luteinizing hormone-human chorionic gonadotropin receptors. Rather. they are present because luteinizing hormone-human chorionic gonadotr opin may regulate bladder functions in women. CONCLUSIONS: A woman's u rinary bladder, which has never been thought of as a gonadotropin targ et, has now been demonstrated to contain luteinizing hormone-human cho rionic gonadotropin receptors. These findings suggest for the first ti me that gonadotropins directly regulate bladder functions in women.