THE PITUITARY BODY 



Cole was able to produce ovulation in the rat, ewe, cow, and 

 sow. Both Cole and Hamburger agree that the seminiferous 

 tubules and interstitial cells are affected in male rats; how- 

 ever, the greater effect is on the interstitial cells. The hyper- 

 trophy of the testis in relation to that of accessory sexual or- 

 gans is greater after pregnant-mare serum than after prolan; 

 however, anterior pituitary extract excels both in this respect 

 (Leonard and Hansen, 1936). The same authors found that 

 the action of pregnant-mare serum is not altered after 

 thyroidectomy. 



Cole (1937) reported that the injection of the hormone into 

 adult female rats at a suitable time (12 rat-units during 

 metoestrus) was followed by pregnancies resulting in an in- 

 creased percentage of large litters. Matings occurred in about 

 half of a series of immature rats receiving daily injections 

 when 26-31 days old. At necropsy about the 10-12 day of 

 pregnancy, more than 20 implanted fetuses could be counted 

 in 38 per cent of the immature rats. There were 17 young in 

 the largest litter born alive. The percentage of fertile matings 

 in immature or adult rats was reduced by large doses of the 

 hormone. 



SUMMARY 



Large quantities of gonadotropic hormone may be liber- 

 ated into the blood stream during pregnancy in man and 

 other primates and in the mare. Presumably, such hormone 

 is important in insuring the maintenance of pregnancy which, 

 especially at first, requires adequate amounts of the internal 

 secretion of the corpus luteum of the ovary. The corpus 

 luteum in turn cannot flourish unless it is furnished with 

 "luteinizing" gonadotropic hormone either by the anterior 

 pituitary or by some other organ. In some animals, for at 

 least part of the period of gestation, the anterior pituitary ap- 

 pears to supply most of the gonadotropic hormone required. 

 In man, however, the chorionic epithelium of the placenta 

 furnishes enormous quantities of luteinizing hormone (pro- 



[148I 



