The Male Sex Hormones

The general effects of castration, in addition to the loss of spermatogenesis, have been known since our earliest historical records. It is not the purpose of this paper to review the earlier studies which emphasize the effects of castration of the male, of transplantation of gonads, and of cryptorchidism on the various physiological, psychical, morphological, and histological changes in the body as a whole and in secondary sex characters and organs. Excellent reviews on the older general and more purely morphological aspects have been written by Lipschiitz (1924), Pezard (1928), Sand (1926, 1932, 1933), Moore (1932) and Steinach (1936). From these and numerous other studies some have concluded that the hypothetical internal secretion of the testicle must have a profound effect on skeletal growth, muscular tone, metabolic rate, hemoglobin and oxidase content of blood and tissues as well as on the control of the secondary sex characters and accessory reproductive organs of the male. This review shows that only very few of these physiological reactions are sufficiently rapid and definite to be used as assay methods in the purification and isolation of the male sex hormones. The action of testis-tissue extracts and concentrates on the rate of metabolism. Brown-Sequard and others have associated the fatigue and “lowered vitality” of advanced age with loss of the internal-secreting function of the testis; hence the early claims of rejuvenation by a hypothetical testicular hormone. The experiment carried out by Brown-Sequard (1889) upon himself is not only the earliest of its type in the field of the testicular hormone but in endocrinology in general. At the age of 72 he prepared very dilute and crude aqueous er:tracts from dog or guinea pig testes and injected them in 1 cc. amounts subcutaneously into himself, irregularly over a period of two weeks. He claimed a remarkable return of physical and mental endurance al d of normal