Effect of Pituitary on Human Uterus. 9 



the non-pregnant and parturient uterus due? The simplest 

 explanation would be that, like the cat's uterus, the human organ 

 changes its innervation, or, rather, during pregnancy its motor 

 innervation becomes predominant. Such, however, is not the 

 case, for epinephrine produces stimulation of the human uterus 

 whether it is pregnant or not. Furthermore, the parturient 

 uterus does not appear to be more susceptible to epinephrine. 

 The only explanation which offers itself is that some substance 

 sensitizes the uterus to pituitary. What this substance is, whether 

 fetal or maternal in origin, I have not yet been able to determine. 

 The sensitizer is certainly not epinephrine, because the previous 

 application of this sympathonimetic amine does not influence in 

 any way the reaction of the non-pregnant organ to pituitary. 

 The difference in response of the two types of uteri throws some 

 light on the discordant results which are said to follow its thera- 

 peutic use. 



Quigley has made a very careful review of the clinical literature. 

 From these reports and his own cases he concludes that pituitary 

 extract is an efficient ecbolic only after labor has begun. Hump- 

 stone declares that pituitary will not induce labor and Hirsch has 

 reported that it is of no value as an abortifacient. Patek claims 

 that pituitary allays threatened abortion while Fischer urges that 

 it be employed to complete a miscarriage. 



These apparently divergent effects may be harmonized by 

 assuming that the uterus must be sensitized before it will respond 

 to the systemic administration of pituitary. During labor the 

 uterus is so sensitized and hence its almost invariable stimulation. 

 In earlier stages of pregnancy the uterus may be sensitized or not. 

 If it is, pituitary will complete abortion or miscarriage. If it is 

 not so sensitized, the administration is not followed by stimulation 

 of the uterus. During threatened abortion a non-sensitized 

 uterus may remain unaffected or it may be depressed. If it is 

 depressed by pituitary the abortion is allayed. If the uterus is 

 not affected the course of the miscarriage is not shortened. 



How early may the uterus become sensitized to pituitary? 

 The experiment on the tubal pregnancy indicates that six weeks 

 after conception pituitary may have a stimulating effect. This 

 also indicates quite clearly that unless we regard tubal rupture as 



