Antiandrogens: Basic Concepts and Clinical Trials

Spermatogenesis and spermiogenesis are hormone- dependent processes. Consequently, hypophysectomy leads to testicular atrophy with arrest of spermatogenesis (Smith, 1930). According to the classical concept of endocrine regulation of testicular function, Leydig cell function (testicular androgen biosynthesis) is controlled by pituitary luteinizing hormone, (LH) while spermatogenesis is controlled by follicle-stimulating hormone (FSH). However, it was soon shown that LH — via stimulation of androgen synthesis — is also important for the maintenance of spermatogenesis in hypophysectomized animals: experiments have demonstrated that spermatogenesis can be maintained in hypophysectomized animals by means of adequate replacement with androgens alone or with androgen precursors, although the doses required are extremely high (e.g., in rats 0.3–1.0 mg testosterone propionate/day/animal subcutaneously).