other hormones 



"Again it should be noted that further investigations of the consti- 

 tuents of salmon waste might prove fruitful. The literature does not 

 present any data on the estrogenic and androgenic hormone content of the 

 salmon genital organs. However, it may be safely assxuned that sexual 

 hormones are present in these organs and, considering the large volume of 

 reproductive tissue available, it is possible that salmon waste would 

 provide another source for the commercial production of these increas- 

 ingly important hormones. 



Another promising opportunity for additional research is presented 

 by the recent discovery of a growth factor present in certain proteins. 

 The present knowledge of the growth factor, called strepogenin, is 

 slight, but it appears that fish flesh is an excellent source. The hor- 

 mone seems to contribute to more efficient protein metabolism and is 

 sometimes termed the "protein utilization factor". Undoubtedly, after 

 processes for the extraction and purification of the growth factor have bean 

 worked out, this material will find a ready market. As mentioned previously, 

 it becomes increasingly obvious that full and efficient utilization of 

 salmon wastes rests upon the instigation of a comprehensive and long term 

 research program in order to fully ascertain the possibilities of the lesser 

 known constituents. 



Miscellaneous Organic Compounds 



The preceding discussions have been confined to more or less specific 

 substances capable of being derived from salmon waste in sufficient quantity 

 for coninercial production. In addition to these compounds, numerous 

 miscellaneous compounds of lesser importance that are normally present 

 in higher animals have been experimentally determined in fish. Those of 

 minor interest include xanthophyl, carotene, astacin, xanthine, carnosine, 

 taurine, betaine, choline, creatine, and creatinine. Others, such as bils 

 acids, guanine, nucleic acid and glutathione, may prove significant in the 

 future pending further development of current research. 



The bile acids have become important in recent years, finding increased 

 use in synthetic organic chemistry and medicine. These acids are secreted 

 by the liver into the duodenum with the gall bladder serving as a reserve 

 storage organ. The bile contents are intimately involved in body metabolism, 

 serving to promote the digestion and absorption of fats in the intestines. 

 The bile acids perform these functions by combining with fatty acids in the 

 intestines to form compounds that are soluble and diffusible into the 

 blood stream. The bile acids are also closely related in structure to 

 cholesterol and are probably formed in the body from cholesterol. This 

 basic configuration, common to cholesterol, bile acids, and sex hormones, 

 enables chemists to synthesize the sex hormones from bile acids collected 

 from mammalian gall bladders. Inasmuch as the cost of mammalian bile is 

 re.ther high and the supply limited, investigations have been carried out 

 to evaluate the economics of fish bile. 



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