History, chemistry and pharmacodynamics of anabolic-androgenic steroids.

It had been known for centuries that castration resulted in the loss of certain secondary male sex characteristics. The first inkling as to the cause of these changes were provided in 1849 by a prevention of the regression of the comb and wattles of capons by implantation of testis into the abdominal cavity of the castrated rooster. The results were correctly interpreted that the testis secreted a substance into the blood to regulate the development and maintenance of the male characteristics. The first active extract of testis, however, was not prepared until 1927. Shortly thereafter (1929), a similar type of activity was found in men's urine which was followed (1931) by the isolation of a pure substance, androsterone. A substance with the properties of the testis extract was quickly (1935) synthesized and proved to be identical to a pure substance, testosterone, obtained almost simultaneously from testis extract. Testosterone influences the growth, development, and function of practically every organ in the body. The chemically and endogenously modified steroids do not have parallel effects on the different biological properties of testosterone. Furthermore animal species and dose of steroid affect the response of the different organs. Many chemically modified steroids and some endogenous steroids of both the C19 and C21 series exhibit definite separation of undesirable biological effects.