THE PITUITARY BODY 



results show that if prolan is still to be considered a secretion 

 of the anterior pituitary, it must be an unusual part of the 

 normal secretion. 



The comparative effects of prolan and anterior pituitary- 

 implants or extract have been observed in hypophysecto- 



FiG. 38. — The effect of prolan on the ovary of a hypophysectomized mature rat. 

 From Leonard and Smith (1934). Left: Persistent corpora lutea in the left ovary 

 removed 78 days after hypophysectomy. Right: The right ovary of the same rat 

 after the injection of 10 rat-units of prolan daily for 10 days. The marked pro- 

 liferation of interstitial tissue makes difficult the recognition of corpora lutea. 



mized female rats by a number of investigators. All agree 

 that prolan, unlike anterior pituitary extract, does not stimu- 

 late follicular growth. Moreover, the effects of prolan de- 

 pend upon the age at which the rat is hypophysectomized, 

 the duration and course of treatment, etc. One of the best 

 reports is that of Leonard and Smith (1934). They admin- 

 istered prolan to immature or older female rats 16-78 days 



[210] 



