THE GONADOTROPIC HORMONES 



sectomy in the rat. According to Lane and Greep (1935), 

 the effects of separated pituitary hormones in immature 

 hypophysectomized rats are as follows: follicle-stimulating 

 hormone causes an increase in the total number of follicles 

 (numerous small primary follicles) and a decrease in the per- 

 centage of vesicular follicles; luteinizing hormone has no ac- 

 tion on the total number of follicles but brings about an in- 

 crease (35-112 per cent) in the proportion of vesicular folli- 

 cles. 



2. Male mammals ."-"^ — A study of the rate of regression of 

 the testes and accessory organs following the removal of the 

 pituitary from 9 guinea pigs has been made by Allanson, 

 Hill, and McPhail (1935). They concluded that maximum 

 atrophy of the testes, epididymides, prostate, and seminal 

 vesicles occurred after about 45 days, although there was 

 marked atrophy of the seminal vesicles after 20-25 days. 

 xAtrophy of the secondary sexual organs occurred at about the 

 same rate after castration. According to Leonard and Ham- 

 ilton (1937), the testis which has been made cryptorchid ex- 

 perimentally degenerates more rapidly (peak at 6 days after 

 operation instead of 10 days), if hypophysectomy is also per- 

 formed. The authors used rats. 



Wells and Moore (1936) found that in the adult or young 

 male ground squirrel {Citellus tridecemlineatus) ^^"^ kept in the 

 laboratory, spermatozoa were produced in December and 

 January. Precocious spermatogenesis and full development 

 of the accessory organs were produced weeks or months in ad- 

 vance of the normal time by gonadotropic substances (pitui- 



^' Koch, Schreiber, and Schreiber transplanted pituitary and testis of immature 

 animals into the anterior chamber of the same eye. They observed, in comparison 

 with control experiments, a definite effect on the germinal epithelium. Guinea pigs 

 were used. 



Bastenie and Zylberszac (1937) injected an anterior pituitary extract into male 

 or female guinea pigs, which also were given colchicine to arrest the mitoses. There 

 were no striking changes in the gonads. Mitotic division was markedly increased 

 in the epithelium of the seminal vesicles and the uterine mucosa. 



^* Wells and Gomez (1937) describe a technic of hypophysectomy in this 

 animal as well as the effects of the operation in males. 



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