STORAGE OF CAROTENOIDS AND OF VITAMINS A 529 



the basal diet. Also, Herbert and Morgan-'^ failed to observe any signifi- 

 cant difference in the hepatic storage of vitamin A in the rat after feeding 

 ^'itamin A or carotene, irrespective of whether or not tocopherols were 

 given to the rats in daily doses of 0.5 to 1.0 mg. Actually, Johnson and 

 Baumann''"^ obtained evidence of a depressing effect exerted by high levels 

 of tocopherol upon the liver stores of vitamin A, and upon the growth of 

 carotene-fed rats. 



Sherman'"^^ suggested that the impro^^ed utilization of vitamin A in the 

 presence of the tocopherols is to be ascribed to the prevention of a physio- 

 logic antagonism between carotene and the unsaturated fatty acids. 



g. The Effect of Carcinogenic Drugs upon Vitamin A Storage. Goerner^^ 

 was the first to show that the injection of the carcinogenic agent, 1,2,5,6- 

 dibenzanthracene, markedly reduced the vitamin A and increased the total 

 lipid content of hepatic mitochondria. On the other hand, it was observed 

 that p-aminoazobenzene, a non-carcinogenic ring compound, had a much 

 less pronounced effect upon liver vitamin A. Subsequently, Goerner and 

 Goerner''''^ found that intraperitoneal injections of 1,2,5,6-dibenzanthra- 

 cene caused a decrease in the total vitamin A stored in the liver, but that 

 the drug was without effect upon the hepatic storage of vitamins C and D. 

 The inhibition of growth caused by the drug paralleled a decrease in the 

 ^'itamin A in the liver. Moreover, the level of glutathione in the liver was 

 unaffected by the administration of l,2,5,6-dibenzanthracene.^°'' 



Baumann and co-workers,^°^ in a further study of this problem, demon- 

 strated that 1,2,5,6-dibenzanthracene caused a reduction m the vitamin A 

 stores in rat liver, not only by increasing the rate of depletion fourfold, 

 but also by preventing the entrance of vitamin A into the liver. The 

 drug was found to be effective, not only when injected in colloidal solution 

 intraperitoneally, but also when administered in oil by the subcutaneous 

 route. No correlation was found to exist between the carcinogenicity of 

 this type of compound and its effect upon ^atamin A. Thus, methylchol- 

 anthrene and benzpyrene, two potent carcinogens, and 1,2-benzanthra- 

 cene, a non-carcinogenic hydrocarbon, all caused a decrease in the quantity 

 of hepatic vitamin A, but they were quantitatively much less effective than 

 was 1,2,5,6-dibenzanthracene. Butter yellow, which is carcinogenic, 

 and carbon black, which is non-carcinogenic, were without effect upon the 

 \itamin A stores in the liver .'^"^ It was likewise noted that the livers of 



70^ R. M. Johnson and C. A. Baumann, /. Biol. Chem., 175, 811-816 (1948). 

 "5 W. C. Sherman, Proc. Soc. Exptl. Biol. Med., 47, 199-200 (1941). 



706 A. Goerner and IM. M. Goerner, /. Nutrition, 18, 441-446 (1939). 



707 A. Goerner and M. M. Goerner, Am. J. Cancer, 37, 518-520 (1939). 



708 C. A. Baumann, E. G. Foster, and P. S. Lavik, /. Nutrition, 21, 431-444 (1941). 



