HORMONES 



that one of the most abundant sources for industrial production is the 

 urine of the staUion (in which it decreases after castration). The urine 

 of men and women also contains estrogens and androgens. The andro- 

 genic hormones, secreted normally by the testicle, can be secreted by an 

 oVary grafted in the ear (Hill) if the ear is maintained at a low tempera- 

 ture. They are also produced by some adrenal tumors and some 

 ovarian tumors (arrhenoblastoma). 



The specificity of response of the reactive organs is not absolute. 

 Androgens can produce some efTects on the endometrium, the vaginal 

 epithelium, or the mammary gland. Estrogens can slightly influence 

 the seminal vesicles. The injection of estrogens can provoke masculine 

 erotization in some adult males, either normal or castrated. 



The relationship between the chemical constitution and the 

 effect of the hormone is so close that a small modification of its mole- 

 cule can profoundly change its actions. Thus, ethyl testosterone pre- 

 pared from the male hormone is very active upon the endometrium. 

 The recent book of Selye shows much of the multiplicity and complexity 

 of the actions of the steroid hormones. 



Synergies and Antagonisms 



It would be impossible in a short essay to enumerate all the 

 cases in which two hormones either strengthen (synergy) or oppose 

 (antagonism) one another's actions. Estrogens in a certain adequate 

 dose prepare the uterus and mammary glands, and sensitize them to 

 progesterone; nevertheless, in other doses these substances can nullify 

 each other's actions. Estrogenic and androgenic hoimones have, in 

 certain cases, antagonistic actions; in others, their actions are inde- 

 pendent and do not interfere with each other; and, finally, some- 

 times they are mutually strengthened. 



Regulation of Secretion of Hormones 



Even though, for each function, several organs play a part, their 

 participation is regulated so as to maintain a steady balance, as is 

 demonstrated by the constancy of the blood sugar level, of the oxygen 

 consumption, of the blood calcium, etc. These regulations are, there- 

 fore, factors in the functional unity of the organism and in the equilib- 

 rium of their functions. 



