ESTROGEN AND PROGESTERONE 



569 



Fig. 9.12. The endometnuin of a castrated monkey that had received 10 /xg. estradiol 

 and 1 mg. progesterone daily for 99 days. 



is lost except for small glandular vestiges 

 along the musciilaris at the base of the en- 

 dometrium. There are no glands, coiled ar- 

 teries, or large blood vessels in what one 

 might yet call the functionalis. All that re- 

 mains is a modified stroma that resembles 

 decidual tissue (Fig. 9.13.4 and B). It is also 

 of interest that these endometria will men- 

 struate if the treatment is discontinued and 

 in most if the injections of progesterone are 

 stopped and estrogen continued, but not if 

 estrogen is stopped and progesterone con- 

 tinued. 



Even though in such experiments the en- 

 dometrium has been under the influence of 

 both estrogen and progesterone for a year 

 and has undergone extremely abnormal 

 modification, it yet is capable of responding 

 to estrogen in a more or less characteristic 

 way when progesterone is stopped and in- 



jections of estrogen continued. Apparently 

 within about three weeks the modified endo- 

 metrium is replaced, under the influence of 

 estrogen, by one that has few glands which 

 tend to be cystic, a mesenchymatous stroma, 

 and no coiled arteries (Fig. 9.14). 



Under similar circumstances, if estrogen 

 is stopped and jjrogesterone is continued, the 

 modified endometrium is lost without bleed- 

 ing and there is almost no repair of the en- 

 dometrium even after a period of 3 weeks. 

 There seems to be an incompatability be- 

 tween the epithelial outgrowths from the 

 mouths of the glands and the underlying 

 stroma of the denuded surface. Conse- 

 quently the epithelium crumbles away and 

 epithelization of the raw surface is not ac- 

 complished (Fig. 9.15j. How long this con- 

 dition could continue has not been deter- 

 mined. 



