694 XI. VITAMINS E (tocopherols) 



reported to ha^^e a low tocopherol content, ^"'^^ although Mason^- demon- 

 strated that this value is dependent upon the intake of \ntamin E in the 

 case of the rat. When the vitamin E intake was increased 100 times, the 

 liver storage was augmented fourteen -fold, in contrast to a rise of only 4 to 

 4.5 times in most other tissues. When the tocopherol intake was increased 

 to 10,000 times the daily minimum requirement, liver storage was further 

 augmented to 150 times and that in the muscle to twelve times that noted 

 when the minimal dosage was given. Thus, the liver pro\'ides a site for 

 tocopherol storage in the rat, and this reser^^e serves to replenish the need 

 of other tissues for vitamin E when the intake of this dietary constituent is 

 less than is required. Mason^^ has recorded the quantity of vitamin E 

 in the several tissues of the rat on a low or a high vitamin E intake. The 

 content in the liver was increased from 8.3 to 1,000 mg. /kg. tissue, that in 

 the muscle from 16.6 to 200 mg. kg. tissue and that in the body fat from 

 20 to 125 mg./kg. tissue on the high level of intake of vitamin E. Cheval- 

 lier et al.^^ found that, during fasting, \atamin E did not decrease in the 

 same proportion as did other lipids, in the rat. Thus it appears that the 

 relative amount of vitamin E and its antioxidant properties increase when 

 the fat content of the organism decreases as a result of inanition. The 

 distribution of \'itamin E in the tissues of the adult rat after the feeding of 

 supplementary a-tocopherol, as observed by Quaife and her co-workers^^ 

 and by Mason,^^ is detailed in The Lipids, ^"ol. I, pages 799 and 800. 



Vitamin E also occurs in the tissues and eggs of chickens and other birds. 

 Although a detailed study of the distribution of vitamin E in the tissues of 

 the hen similar to that carried out on the rat is not available, it is known 

 that vitamin E occurs in the egg, and that the amount becomes propor- 

 tionally higher with progressively increasing doses. ^'* a-Tocopherol is 

 absorbed and deposited in the hen, as in the cow and human, in preference 

 to the other tocopherols ; therefore this variety predominates in the tissues 

 and eggs of chickens. ^^ The efficiency of transfer of the tocopherols to the 

 egg of the hen was reported by Quaife et al.^^ as 22.1% for the a-compound, 

 3.6% for 7-tocopherol, and 2.0% for 5-tocopherol. There is no evidence 

 in any of these studies of an in vivo transformation of one tocopherol into 

 another. 



^ W. F. J. Ciithbertson, R. R. Ridgewav, and J. C. Drummond, Biochem. J., 34, 34- 

 39(1940). 



'1 T. Moore, A. J. P. Martin, and K. R. Rajagopal, Vitamin E Symposium, April 22, 

 1939, Soc. Chem. Ind. Food Group, 1940, 41-43. 



82 K. E. Mason, /. Nutrition, 23, 71-81 (1942). 



^' A. Chevallier, R. Schneider, and C. Burg, Compt. rend. soc. bioL, 144, 1394-1396 

 (1950). 



s^ G. L. Barnum, /. Nutrition, 9, 621-635 (1935). 



