ABSTRACT
In 1849 Professor Berthold at the University of Gottingen made the landmark ob servation that the characteristic male plumage of cockerels can be maintained in the caponized birds by simply implanting a testis in the abdominal cavity. This observation started the search for the blood-borne chemical mediator later called “the internal secretions” by Claude Bernard and ushered in the beginning of en docrinology. Forty years later, the French physician Brown-Sequard again star tled the scientific community by announcing at the age of 72 that he had succeeded in a dramatic self-rejuvenation by injecting himself with an extract of dog testi cles. During the next 50 years, the claim of Brown-Sequard and supporting state ments found in ancient medical texts, such as the Ayurveda of Susruta (c. 1000 BC) recommending animal testicles as a remedy for impotence, may have led to the rush for both homologous and heterologous testicular transplants in men de sirous of improving their sexual ability or regaining their youthful vigor (17). At the beginning of the twentieth century one of the major proponents of the testic ular transplant, Dr. Serge Voronoff, traveled all around the world to perform het erologous transplantation of monkey testes into older men. Unfortunately, much of the initial excitement of the dramatic therapeutic claims of the testicular ex tracts and testicular transplants did not survive careful scientific scrutiny. How ever, interest in the subject was strong enough to generate working hypotheses and experimental designs that eventually resulted in the isolation and character ization of testosterone, the male sex hormone. Later studies revealed that testos terone exerts profound physiologic effects not only on the reproductive organs but also on the skeletal muscle and can even influence animal behavior. The ini tial report of Kochakian that the androgenic component of human male urine causes positive nitrogen balance and increases the body weight of castrated dogs
was immediately confirmed in humans (22,23). These observations led to the view that the anabolic or myotropic action of androgens is distinctly different from its well known reproductive actions.
