BODY TISSUES 



323 



CH., 



progesterone 



Stilbestrol is a synthetic estrogen derived from stilbene (C^Hj-CH : 

 CH-CcHr,). It is not chemically related to the natural estrogens, but 

 the diethyl derivative is about three times as potent as estrone. This 

 compound has found wide use in modern medical practice as a supple- 

 ment to the natural supply of estrogens. 



C,H5 



HO- 



\-C=C-/ \-OH 



C2H5 



dietliylslilbestrol 



Many plants contain estrogenic substances in varying quantities 

 which may be factors in the growth of animals. The administration of 

 sex hormones to ruminants, swine, and poultry increases the growth 

 rate and efficiency significantly. Hormones are implanted subcutane- 

 ously for slow release or given by mixing with the feed (page 421). 

 Diethylstilbestrol is used quite extensively in animal and poultry hus- 

 bandry. This hormone presumably induces the tranquilization of the 

 male without castration. 



TESTICULAR HORMONES. Hormoues produced by testicular tissues are 

 known as androgens. They are also present in urine. Although they 



testosterone 



androsterone 



are termed male sex hormones, they have certain estrogenic properties. 

 So far as the male is concerned, these hormones serve to bring about 



