474 IX. CAROTENOIDS AND VITAMINS A 



Goodwin and Wilson^'^^ were unable to verify this finding. Bodansky and 

 Markardt'^° found that 3-/3-acetoxy-17-a-hydroxyallopregnan-20-one 

 (''Compound L") which, they state, ^*° was isolated from the adrenal gland 

 by Reichstein,^^^ decreases plasma vitamin A when injected into male 

 rats. Apparently the decrease in the plasma vitamm A level occurs con- 

 comitantly with an increased deposition in the liver. ^^^ 



Season is a factor which must be taken into consideration with respect 

 to the level of vitamin A and of carotene in the plasma, particularly in the 

 case of cattle. Braun^^^ recorded a maximum average of 43.5 jug. % 

 (145 I.U.) in March for the plasma vitamin A of Holsteins, while the 

 minimum level of September and October samples w^as 10 ng. % (33 I.U.). 

 Lqj.(J319 reported similar variations in Ayrshire cows, with a maximum 

 figure of 45 ng. % (150 I.U.) when on summer pasturage, and a minimum 

 average of 9.3 jug. % (31 I.U.) during stall feeding in the winter. No sea- 

 sonal variations in plasma vitamin A levels have been observed in school 

 children.^"" 



(c) Pathologic Factors Altering Blood Vitamin A. Diabetes mellitus is 

 believed to be associated with impairment of the conversion of carotene to 

 vitamin A. According to a number of workers, ^"-~^-* the carotenemia is 

 associated with a low plasma vitamin A, although Kimble et al.^^'^ were un- 

 able to demonstrate any reduction of vitamin A in 116 unselected cases of 

 diabetes, prior to hospitalization. 



Acetonemia in cattle has been found to be associated with an extremely 

 low plasma vitamin A level (1.2 /xg. % or 4 I.U.) and an unusually high 

 level of plasma carotene. ^^^ It is suggested that inadequate transformation 

 of carotene to vitamin A may be the cause of the low level of vitamin A in 

 the plasma. The acetonemia has been successfully treated by a number 

 of investigators,^^^"^*^ by the administration of vitamin A. 



Liver disease may likewise result in abnormally low levels of plasma vita- 

 min A. Thus, Harris and Moore'^^^ reported a level of 16.4 ixg. % (54.7 

 I.U.) in hepatitis, which increased to 35.4 ng. % (118 I.U.) when a cure 

 was effected. Low vitamin A values were reported in cases of liver dis- 

 ease in man. ^^^'^^2"^^* A decrease in plasma vitamin A was noted in 

 pneumonia. ^^^ No changes could be demonstrated in this value in children 



"9 T. W. Goodwin and A. A. Wilson, Biochem. J., 45, 370-372 (1949). 



380 O. Bodansky and B. Markardt, /. Biol. Chem., 190, 83-93 (1951). 



381 T. Reichstein, Helv. Chim. Acta, 19, 29-63, 402-412 (1936). 



382 N. Fiessinger and H. Torres, Compt. rend. soc. bioL, 135, 636-637 (1941). 



383 ]\f Fiessinger, H. Torres, and A. Gasnier, Compt. rend. soc. biol., 135, 697-698 

 (1941). 



384 H. Popper, F. Steigmann, and Z. Zevin, /. Clin. Invest., 22, 775-783 (1943). 



