THE PITUITARY BODY 



characterized both by an increase in the number and size of 

 basophils and by an increase in the gonadotropic potency of 

 the pituitary. In the guinea pig, however, no similar mor- 

 phological change occurs, yet the gonadotropic potency is 

 increased. The injection of oestrin is known to decrease the 

 gonadotropic potency of the pituitary; in the rat, however, 

 the cells of the pars glandularis are said to be characterized 

 by a basophilia after the production of persistent oestrus fol- 

 lowing oestrin injection (Charipper and Haterius, 1932; but 

 Nelson, 1935, reported that the change consisted of a loss of 

 granules by both oxyphils and basophils). In man, the an- 

 terior pituitary of spayed or castrated individuals appears to 

 secrete an increased amount of follicle-stimulating hormone; 

 the anatomical changes, however, concern chiefly the oxy- 

 phils. Cytological changes in the pituitary of female rats at 

 different stages of the oestrous cycle also suggest that the 

 oxyphilic cells secrete a follicle-stimulating hormone. More- 

 over, there seems to be a greater amount of gonadotropic 

 hormone in the pituitary of the male rat than in that of the 

 female (Evans and Simpson, 1929; Lipschiitz and Reyes, 

 1932);^ this difference may be related to the greater propor- 

 tion of chromophils — particularly oxyphils — in the pars 

 glandularis of the male rat. 



From studies of the pituitary of the frog, Zahl (1935) con- 

 cluded that changes in the gonads and sexual activity could 

 be correlated with cytological changes chiefly in the oxyphils. 



The thyrotropic hormone has been thought to be a secre- 

 tory product of the basophilic cells in studies of the pituitary 

 of the ox and toad (see chap. vii). 



The presence of gonadotropic hormones in parts of the hu- 

 man pars glandularis, thought to consist predominantly of 

 cells of one type, has been investigated by Philipp (1930), 

 Kraus (1932-33), and Zondek (1933). Some of the observa- 

 tions have already been discussed. Apparently gonadotropic 



' Also see chap. iv. 



[30I 



