THE PITUITARY BODY 



zoate potentiates the response of the chick's testis to sheep 

 pituitary extract. 



Observations like those of Breneman illustrate the com- 

 plexity and difficulty of interpreting the reported effects of 

 "sex" hormones on the gonadotropic phase of pituitary func- 

 tion. It is necessary to take into account depressant (and 

 perhaps excitatory) effects'*^ on the secretion of gonadotropic 

 hormones as well as substitution-effects on the gonad itself 

 after the removal of the pituitary. For some years the view 

 that "male sex hormone" may lessen the secretion of gonado- 

 tropic hormone and thus bring about testicular or ovarian 

 damage has been accepted and can again be illustrated by re- 

 cent observations in rats. Oestrus, as judged by the vaginal 

 smear, may be prevented in the adult female rat by large 

 doses'^^ of several androgens such as testosterone, androster- 

 one,^" androstanedione, and androstenedione (Browman, 1 937 ; 

 Nelson and Merckel, 1937). Androgens may completely pre- 

 vent ovarian hypertrophy in the female of the parabionts 

 9 sf, if administered to the castrated male (Hertz and Meyer 

 1937). The inhibitory effect of three androgens corresponded 

 to their potency as "male hormones" (e.g., testosterone pro- 

 pionate > testosterone >dehydroandrosterone). Hain (1937) 

 concluded that testosterone propionate antagonizes the 

 oestrogenic effect of oestrone in the spayed rat — a conclusion 

 not in accord with the usual view that antagonism of the se- 

 cretion of the intact ovary by a male hormone is the indirect 

 result of depression of pituitary function. Hain also found 

 that large doses of androgens such as testosterone or its pro- 

 pionate, and transandrostenediol cause abortion in the rat 



^^ Pfeiffer's results led to the conclusion that the normal internal secretion of the 

 rat's testis prevents or inhibits the liberation of luteinizing hormone by the pars 

 glandularis. 



'"0.5-5 "ig- daily. Nelson and Merckel usually injected 0.5-1.5 mg. daily for 

 as long as 30 days. 



5" According to Biihler {1936) crystalline "Proviron" (androsterone.'') does not 

 inhibit the growth of the uterus and ovaries of immature rats receiving 30-50 capon- 

 units in 8 days. 



[90] 



