The urinary bladder of a woman is a novel site of luteinizing hormone human chorionic gonadotropin receptor gene expression

OBJECTIVE: The female reproductive tract contains functional luteinizing hormone-human gonadotropin receptors; therefore our objective was to test the hypothesis that bladder trigone, which is derived from intermediate mesoderm along the urogenital ridge during embryonic development of the female reproductive tract, may also contain these receptors. STUDY DESIGN: Bladder trigones or domes were biopsied from 15 premenopausal and 19 postmenopausal women undergoing surgical correction of genital prolapse, incontinence, or both. The biopsy specimens were submitted for luteinizing hormone-human chorionic gonadotropin receptor analysis by in situ hybridization and immunocytochemical examination. The receptor immunostaining was visually scored by 3 investigators without knowing the identity of the menopausal status. RESULTS: In situ hybridization demonstrated the presence of receptor transcripts, and immunocytochemical examination revealed the presence of receptor protein in bladder trigone. The bladder trigones from postmenopausal women contained lower levels compared with those from premenopausal women, implying that luteinizing hormone might down-regulate its own receptors. Transitional epithelium contained the highest receptor levels followed by smooth muscle and blood vessels. The bladder dome contained receptor levels similar to those in trigone, which suggests that a common embryologic origin is not the only reason for bladder trigone containing the luteinizing hormone-human chorionic gonadotropin receptors. Rather. they are present because luteinizing hormone-human chorionic gonadotropin may regulate bladder functions in women. CONCLUSIONS: A woman's urinary bladder, which has never been thought of as a gonadotropin target, has now been demonstrated to contain luteinizing hormone-human chorionic gonadotropin receptors. These findings suggest for the first time that gonadotropins directly regulate bladder functions in women.