IX. OCCURRENCE 



549 



in mice which could be counteracted by nicotinic acid or tryptophan. These 

 findings have not been confirmed. Indeed, Gaebler and Beher^^ found that 

 3-acetylpyridine caused large increases in urinary N'-methylnicotinamide 

 excretion in dogs and rats, indicating that this compound could serve as a 

 precursor of nicotinic acid. Beher et alJ'' later used an isotope tracer tech- 

 nique to prove the conversion of 3-acetylpyridine to nicotinic acid. How- 

 ever, Ackermann and Taylor"^ found that 3-acetylpyridine induced rapid 



TABLE XVI 



Nicotinic Acid Content of Various Organs and Tissues 



(y/g. of wet tissue) 



death in embryonating eggs, an effect competitively reversed by nicotin- 

 amide but much less successfully reversed with nicotinic acid or trypto- 

 phan. Hull et al?^ reported that 3-acetylpyridine and pyridine-3-sulfonic 



75 D. W. Woolley, /. Biol. Chem. 162, 179 (1946). 



'6 O. H. Gaebler and W. T. Beher, J. Biol. Chem. 188, 343 (1951). 



" W. T. Beher, W. M. Holliday, and O. H. Gaebler, Abstr. 12th Intern. Congr. Pure 



and Appl. Chem., New York, p. 84 (1951). 

 "* W. W. Ackermann and A. Taylor, Proc. Soc. Expil. Biul. Med. 67, 449 (1948). 

 '8 W. Hull, J. C. Perrone, and P. L. Kirk, /. Gen. Physiol. 34, 75 (1950). 

 7« Averaged from the data of A. Taylor, M. A. Pollack, and R. J. Williams, Univ. 



Texas Publ. 4237, 41-55 (1942). 



80 A. Lwoff and L. Digonnet, Compt. rend. 213, 1030 (1941). 



81 H. K. Mitchell and E. R. Isbell, Univ. Texas Publ. 4237, 37-40 (1942). 



