OCCURRENCE OF THE VITAMINS E 693 



E. In confirmation of their earlier work,^'- Hanson and co-workers^^ 

 found that only dietary a-tocopherol could restore the stabihty of the bod}' 

 fat of rats pre^'iously maintained on a vitamin E-free diet. The addition 

 to the diet of other well-known antioxidants, including ascorbic acid 

 (\'itamin C), hydroquinone, a-naphthol, nordihydroguaiaretic acid (ND- 

 GA), or lecithin was found to be ineffective in increasing the keeping 

 qualities of the bodj' fat. For a discussion of these and other antioxidants, 

 the reader is referred to The Lipids, Vol. I, pages 288 to 299. It is be- 

 lieved that the onlj^ compounds deposited in the adipose tissues which are 

 effective antioxidants are the \'itamins E. 



a-, I3-, and 7-Tocopherols were all found to be capable of deposition in 

 animal fats when fed in the diet to rats pre^'iously on a vitamin E-free 

 diet.^^ The amounts of a- and /3-compounds deposited were quite similar, 

 as judged from the resulting stabihty of the fats; on the other hand, the 

 amount of 7-tocopherol laid do\Aii in the adipose tissue was much less. In 

 all cases the storage required seven days or more to reach the maximum. 

 No differences were noted between the ability of natural and that of s\ti- 

 thetic tocopherols to serve in this capacity.^^ 



With the possible exception of a crustacean, the water flea (Daphnia 

 magna), ^^ there is no evidence that the tocopherols ai-e required b\' the in- 

 vertebrates or, in fact, that they are stored in the tissues of these animals. 

 Although many fish liver oils may contain appreciable amounts of the 

 vitamins E, cod liver oil is generally considered to be completely devoid 

 of these substances."^ However, Quackenbush and co-workers*^ recorded 

 an appreciable content of 26 mg. % of cod liver oil. Bocchi*^ observed 

 some \'itamin E in tuna liver oil, and Robeson and Baxter** noted small 

 amounts in the liver oils of the shark (Mangona) (10 mg. % oil), and of 

 the soupfin shark (Galeorhinus zyopterus) (4 mg. % oil). 



In the case of the rat, the highest concentration of tocopherol was found 

 in the pituitarj^ gland (h\T3ophysis) , while the next highest concentration 

 occurred in the suprarenal glands.*^ The li^'er, which is the usual storage 

 organ for fat-soluble \'itamins and other physiologic compounds, has been 



8< H. T. Hanson, R. H. Barnes, W. O. Lundburg, and G. O. Burr, /. Biol. Chem., 156, 

 673-677 (1944). 



^ W. O. Lundberg, R. H. Barnes, M. Clausen, N. Larson, and G. O. Burr, /. Biol. 

 Chem., 168, 379-389 (1947). 



8« F. W. Quackenbush, H. L. Gottlieb, and H. Steenboek, Ind. Eng. Chem., 33, 1276- 

 1278(1941). 



8' L. Bocchi, Ateneo pannense, 10, 107-126 (1938); Chem. AbsL, 33, 2945 (1939). 



8« C. D. Robeson and J. G. Baxter, J. Am. Chem. Soc, 65, 940-943 (1943). 



*^ M. L. Quaife, W. J. Swanson, M. Y. Dju, and P. L» Harris, Ann. New York Acad. 

 Sci.,52, 300-305 (1949). 



