STEROID HORMONES 



thesis, but provides a new approach to the investigation of steroid 

 synthesis. 



It is customary to think of three principal glands as the endog- 

 enous steroid hormone factories; these are the testes, the ovaries, 

 and ihe adrenal cortex. There are numerous demonstrations of 

 folliculoid material in animal fluids, especially in liver and bile. 

 Estriol, estrone, and estradiol have been isolated from human placenta 

 and there have been indications of the presence of progesterone in 

 this organ; but the placenta as a synthesizing organ may be con- 

 sidered as a rather special case. In brief, the presence of notable 

 hormonal activity in certain tissues cannot be taken as prima Jacie 

 evidence that the hormones are produced in these tissues. For this 

 reason our concepts even of the sites of steroid hormone synthesis are 

 in a state of flux. 



The female in full reproductive vigor leads a double life; she 

 is alternately mate and mother. According to current concepts, two 

 ovarian hormones are primarily responsible for this rhythm of func- 

 tion, estradiol and progesterone. Estradiol, the hormone of the 



CH:, 



OH 



c=o 



O 



H3C 



H3C 



HsC 



/\ 



/^ 



/\ 



H3C 



/\ 



HO- 



O- 



/X 



Estradiol 



Progesterone 



HO- 



Estrone 



ovarian follicle, is considered responsible for the estrous phenomena 

 that culminate in mating, and progesterone, the hormone of the corpus 

 luteum, is responsible for the maintenance of pregnancy. Doisy and 

 his collaborators, in 1936, isolated and chemically identified estradiol 

 from sow ovarian tissue; and in 1934 progesterone from luteal tissue 

 was chemically identified by four separate groups of investigators. 

 The uniqueness of progesterone as the ovarian luteoid is not open to 

 question, but the evidence is fairly clear that another folliculoid, 

 estrone, also arises from ovarian tissue. Westerfeld and collaborators 

 found it to occur in sow ovarian tissue in an amount nearly equal to 

 that of estradiol, and Dr. J. Schiller and the writer have recendy 



307 



