THE PITUITARY BODY 



late markedly the activity of the interstitial cells so that 

 more of the internal secretion characteristic of the testis is 

 liberated. In adult hypophysectomized male animals, how- 

 ever, prolan will maintain both the gametogenetic and in- 

 ternal secretory functions of the testis; this is not the case in 

 hypophysectomized female animals. There is evidence that 

 the hypothetical "B" (luteinizing) fraction of prolan is re- 

 sponsible for the stimulation of the interstitial cells. Brin- 

 deau, Hinglais, and Hinglais (1934) stated that they isolated 

 a purely luteinizing fraction from pregnancy-urine which 

 caused the testicular changes characteristic of prolan in im- 

 mature mice. Frequently, also, stimulation of the interstitial 

 cells can best be obtained from those samples of prolan caus- 

 ing the most pronounced luteinization. 



Apparently in some fish prolan may cause stimulation of 

 spermatogenesis. Boucher, Boucher, and Fontaine (1934) 

 injected a total dose of 6-15 cc. of pregnancy-urine over a 

 period of 1 weeks or more into immature male silver eels. So 

 marked was the stimulation of spermatogenesis that the 

 testes had the appearance of approximately normal sexual 

 maturity. Rugh (1935) caused the clasping reflex to appear 

 in male amphibia {R. catesbiana and Bujo Jowleri) by in- 

 jecting prolan. xAll investigators agree that prolan has no 

 effect on the gonads of the male bird. 



The effect oj prolan on the genital tract oj the male mouse and 

 rat. — Qualitatively there appears to be no difference in the 

 gonadotropic effects of prolan in immature mice and rats. 

 Some believe, however, that the rat responds more readily 

 than the mouse. In the first reports (1929) by Brouha and 

 Simmonet, and Engle, who injected pregnancy-urine into 

 immature mice and rats, there appeared discrepancies in re- 

 sults and interpretation. Engle found that the chief effect 

 was a stimulation of interstitial tissue with secondary effects 

 on the accessory sexual organs; the injections also appeared 

 to cause some destructive changes in the seminal epithehum 



