The Endocrinology and Developmental Biology of the Prostate*

MALE accessory sex glands such as the prostate, seminal vesicle, and bulbourethral gland have served in various capacities as models for investigating the action of androgens in regulating epithelial growth, RNA and protein synthesis, and secretory activity. The most extensively studied gland of this group is the prostate. This gland is found exclusively in mammals and produces many components of semen such as fructose, zinc ions, and various proteins important for the formation of the copulatory plug in rodents. The impetus for investigating regulation of prostatic growth and function stems in part from the many pathological complications which affect this gland. The prostate is the site of various types of inflammatory and infectious conditions (1) as well as benign and malignant proliferative changes in aging males. Despite extensive research, little of the pathogenesis or natural history of these diseases has been elucidated (2). Benign prostatic hypertrophy (BPH), a disease in which the prostate resumes growth late in life, is the most common nonmalignant proliferative abnormality found in any internal organ (2). The incidence of BPH rises from 23% in men at 40 yr of age to 88% by the ninth decade (3). Adenocarcinoma of the prostate is the third leading cause of cancer deaths among men. Approximately 69 cases/100,000 men are diagnosed each year in the United States. It remains an intriguing paradox that malignant prostatic tumors are among the most prevalent neoplasms in men, while the seminal vesicles and bubulbourethral gland remain nearly immune to neoplastic change (<1 case of carcinoma of the seminal vesicle per year) (4).