The Question of Sex Hormone Antagonism. ∗

The preparation of active hormone substances in the Department of Physiological Chemistry and Pharmacology and the development of testis hormone detection methods for the laboratory mammal in the Department of Zoology has enabled the Chicago group 1 during the last 4 years to study more directly, by injections, the effects of separate or combined sex hormone action in the rat.†

The results here given have been the basis for a new conception regarding the interaction of hypophysial and gonadal secretions in the organism, which effectively removes the troublesome notion of sex hormone antagonism as an interpretation.

Injections into the castrated male gave results upon the male accessories (prostate gland and seminal vesicles) as follows: I. Oestrin—no effect; II, testis hormone—normal accessories; III, testis hormone + oestrin—normal accessories. No antagonism is evident with mixtures of gonad hormones. Injections into normal males gave IV, oestrin—testicular damage, castrate accessories; V, oestrin + testis hormone—testicular damage, normal accessories; VI, brain, heart or liver lipoids—normal or damaged testes and normal accessories. VII, Cryptorchidism caused marked testis damage but normal accessories.

We have advanced the working hypothesis that gonadal hormones suppress the hypophysis, making available to the organism a reduced amount of gonadal stimulating secretion; that hypophysis hormone is necessary for gametogenesis or hormone production by the gonads; that sex hormones act directly upon homologous accessories, with or without the presence of hypophysis secretion, and have no effect upon heterologous accessories; and that sex hormones have no direct action upon the gonads.