x. effects of deficiency 563 



9. Eyes 



Hubbard and Wald'"^ have shown that DPN is necessary for the con- 

 version of vitamin Ai to rhodopsin, a process essential to vision. In this 

 instance, a ready-made biochemical explanation is available for a defect 

 which has not been noted in either human or animal nicotinic acid de- 

 ficiency. 



Simonelli^"^ found that cataractous lens (produced by massage) in rabbits 

 have a nicotinic acid concentration one-fifth to one-half of normal. The 

 same was true for cataracts induced by naphthalene. The concentration of 

 nicotinic acid in the crystalline lens from two humans with cataract seemed 

 to be slightly reduced. Pike^°* found that nicotinic acid had an effect in 

 preventing congenital cataract in rats. The effect seemed to be due to the 

 "sparing" effect of nicotinic acid on tryptophan. Large amounts of nicotinic 

 acid were ineffective if dietary tryptophan was too low. Cataract from 

 tryptophan deficiency is well known. 



10. Blood 



Anemia is an almost constant finding in human pellagra. It is generally 

 mild and may be macrocytic or normocytic hypochromic in type. The white 

 cell count is generally normal.^* There is no certainty that this anemia is 

 due specifically to nicotinic acid deficiency. It does generally improve fol- 

 lowing nicotinic acid therapy, but most often other B vitamins, yeast, or 

 wheat germ as well as a generous diet are used in therapy. This could 

 provide adequate amounts of other vitamins, such as folic acid, which 

 may be more directly concerned in the anemia. Complicating deficiencies 

 of vitamins other than nicotinic acid almost certainly were present in some 

 of the early experiments showing that dogs and swine on Goldberger diets 

 developed anemia as well as leucopenia and granulocytopenia. ^"^""^ How- 

 ever, later studies in swine, where complicating deficiencies were minimized, 

 revealed a normocytic anemia."^ Wooley^" found a mild anemia, leucopenia, 

 and granulocytopenia in nicotinic acid-deficient rabbits which responded 

 to therapy with either nicotinic acid or tryptophan. Rats and dogs do not 

 usually develop anemia in nicotinic acid deficiency on diets otherwise com- 



"6 R. Hubbard and G. Wald, Science 115, 60 (1952). 



10' M. Simonelli, Boll. soc. ital. biol. sper. 20, 692 (1945). 



108 R. L. Pike, J. Nutrition 44, 191 (1951). 



109 D. K. Miller and C. P. Rhoads, /. Clin. Invest. 14, 153 (1935). 

 ii" C. P. Rhoads and D. K. Miller, /. Exptl. Med. 58, 585 (1933). 

 1" D. K. Miller and C. P. Rhoads, J. Exptl. Med. 61, 173 (1935). 

 "2 T. Spies and A. Dowling, Am. J. Physiol. 114, 25 (1935). 



"3 G. E. Cartwright, B. Tatting, and M. M. Wintrobe, Arch. Biochem. 19, 109 (1948). 



