Synergistic Effect of Anterior Pituitary and Male Hormone

Abstract

The sex hormones of the anterior pituitary are not sex specific, but stimulate the secretion o i the inale as well as the female sex glands. However, for the same (lose of hormone the effect on the female is far more striking than the effect on the male. I n connection with other work in this lalioratory, and prompted by the recent work of Funk ant1 Harroiv,' we carried out experiments to increase the,stimulating effect of the anterior pituitary hormone on the male sex glands by siniultaneous injections of male hormone.These experiments ivere done on our laboratory albino rats. Eight rats of approximately equal age and weight were divided into 4 groups of 2 each : ( 1 ) control : ( 2 ) injected with anterior pituitary hormone ; ( 3 ) iiijected with male hormone ; (4) injected with both anterior pituitary and male hormone. &All injections were made intramuscularly and twice daily. -At autopsy the whole genital tract was exposed and the seminal vesicles and testes inspected macroscopically, and weighed. The solution of the anterior pituitary was prepared from fresh glands and standardized by the Zoiidek-Aschheim technic to contain 100 mouse units in each cc. This solution was a mixture of the maturing and the luteinizing fractions as determined by previous assay on female rats.The solution of the male hormone was prepared from fresh testes and tested on the castrated rooster for its ability to restore secondary sex characteristics. Each cc. contained approximately 5 cock unit. A cock unit is the amount of hormone necessary to cause an increase of 20% in the size of the comb and wattles in the course of 10 clays. The solution of male hormone was purposely made quite dilute to preclude the possibility of any great amount of activity originating from this solution. In every case? the male hormone was itself inactive in the doses employed. In the following experiments mature and immature rats lvere injected twice daily over varying periods of time, and the seminal vesicles and testes examined for a degree of hypertrophy, content of secretion, ramifica-1 Funk, C., and Harrow, B., A m .