Role of the prostate in the regulation of pituitary secretion of follicle stimulating hormone.

The secretion of Follicle Stimulating Hormone by the pituitary gland is not regulated entirely by the negative feedback from gonadal steroids. There is ample evidence that the secretion of FSH is regulated by a non-steroidal hormone of gonadal origin termed "inhibin". Using a radioimmunoassay procedure, immunoreactive inhibin-like material was quantified in tissue and biological fluids to study its role in reproductive pathophysiology. High levels of immunoreactive inhibin were observed in human prostate as compared to testis. Biologically active as well as immunoreactive inhibin-like material (ILM) was obtained from human prostate, and was similar to that obtained from human seminal plasma under identical conditions. In patients with benign prostatic hypertrophy, high inhibin levels were observed which reduced after prostatectomy. The presence of immunoreactive inhibin in urine as well as semen of vasectomized and gonadectomized subjects indicates that prostate also secretes inhibin-like material. The specific receptors for inhibin as well as biosynthesis of inhibin in human prostate have been reported. Elevation of serum FSH levels following castration of adult male rats was further enhanced in animals where castration as well as prostatectomy was carried out. All these results demonstrate that apart from the testis, the prostate also secretes ILM and further suggest that the prostate along with testis, may play an important role in the regulation of pituitary secretion of FSH.