STORAGE OF CAROTENOIDS AND OF VITAMINS A 527 



the administration of thiouracil or thiourea, the depletion of hepatic stores 

 was delayed. A three-fold increase in metabolic rate (produced by thyroid 

 powder) was found to be quantitatix-ely less important for the retention of 

 vitamin A than a decrease in growth rate of 50%. Thiourea resulted in a 

 particularly low content of vitamin A in the kidnej'-s. 



e. The Effect of the Method of Administration on the Storage of Vitamin 

 A. Teulon ct al. obser\-ed that the storage of vitamin A in the liver 

 was greater, and occurred sooner, when oil solutions of vitamin A were 

 given orall}^ than when the intramuscular route^^^ or subcutaneous injec- 

 tion^^* was employed. On the other hand, Esh and Bhattacharya^^'' re- 

 ported that vitamin A alcohol or acetate gave rise to higher hepatic stores 

 of vitamin A when administered orally in a 20% Tween 20 solution than 

 when fed in an ethyl oleate or peanut oil solution. No significant difference 

 obtained in liver storage when natural or when synthetic vitamin A was 

 used.««* 



f. The Effect of Tocopherols on Vitamin A Storage. Moore^^^ was the 

 first to suggest that the vitamin E (tocopherol) intake has an important 

 bearing on the ability of the animal to lay down administered vitamin A. 

 Davies and Moore, '^'^^ and more recently Dubouloz and associates, ^^^ also 

 came to similar conclusions. According to the latter, about 22% of the 

 vitamin A disappearing from the gastrointestinal tract of the rat was 

 stored in the liver when tocopherol or natural antioxidants were used, 

 while the figure was only 14.5% in the absence of antioxidants. Hick- 

 man^*- in a review, and with his co-workers,*^^"''"^ called attention to the 

 synergism exerted by the tocopherols upon the utilization of carotene and 



693 jj Teulon, C. Marnay, and H. Gounelle, Compt. rend. soc. bioL, 145, 831-834 

 (1951). 



69" H. Teulon, C. Marnay, and H. Gounelle, Compt. rend. soc. biol, 144, 1546-1548 

 (1950). 



"5T. Moore, Biochem. J., 34, 1321-1328 (1940); with I. M. Sharman, Brit. J. 

 Nutrition, 5, 119-129 (1951). 



69« A. W. Davies and T. Moore, Nature, 147, 794-796 (1941). 



«"P. Dubouloz, G. Pistone, and R. Marville, Bull. soc. chim. biol, 31, 1273-1278 

 (1949). 



"8 K. Hickman, P. L. Harris, and M. R. Woodside, Nature, 150, 91-92 (1942). 



*9' K. C. D. Hickman, P. L. Harris, and M. R. Woodside, Vitamin A and E Inter- 

 relationships, presented before Am. Chem. Soc, 104th meeting, Buffalo, Sept. 7-11, 

 1942; also presented before Gibson Island Conf., Am. Assoc. Advancement Sci., Sect, on 

 Vitamins, Julv, 1942; cited by K. Hickman, Ann. Rev. Biochem., 12, 353-396 (1943), 

 p. 382. 



^»« K. C. D. Hickman, iM. W. Kaley, and P. L. Harris, J. Biol. Chem., 152, 303-311 

 (1944). 



^" P. L. Harris, M. W. Kaley, and K. C. D. Hickman, /. Biol. Chem., 152, 313-320 

 (1944). 



