550 NIACIN 



acid produced deleterious effects in embryonic chick heart cultures, but 

 nicotinic acid would not reverse this effect. Available evidence seems to 

 support the view that 3-acetylpyridine is a nicotinic acid antagonist under 

 certain conditions. However, animals (rat and dog at least) possess the 

 ability to convert this compound to nicotinic acid. If the antagonist is 

 administered in doses large enough to exceed the animal's capacity to con- 

 vert it to nicotinic acid, then it acts as an antagonist. If given in lower doses 

 it does not act as an antagonist but will actually substitute for nicotinic 

 acid. There is no evidence that either 3-acetylpyridine or pyridine-3-sulfonic 

 acid occurs in food. 



H. OCCURRENCE IN VARIOUS TISSUES 



The data in Table XVI are presented to give a picture of the relative 

 distribution of nicotinic acid in various mammalian tissues and organs. 

 The data are not necessarily exactly comparable from one species to an- 

 other, because different analytical methods were used. Gounelle and associ- 

 ates^^ found considerably higher values for normal human liver (150 7 per 

 gram) than that reported by Taylor et alP (Table XVI). 



X. Effects of Deficiency 



A. IN MICROORGANISMS 



E. E. SNELL 



Subsequent to the discovery of diphospho- and triphosphopyridine nu- 

 cleotides and the demonstration that these nicotinamide-containing coen- 

 zymes were identical with the long-known factor V required for growth of 

 Hemophilus influenza, nicotinic acid itself was shown to be an essential 

 growth factor for Staphylococcus aureus^ and for Corynehacterium diph- 

 theriae? Since then, it has been shown to be essential for a great variety of 

 other bacteria (e.g., Proteus vulgaris, Aceiobacter, all lactobacilli so far 

 examined, Clostridium tetani, and others*- *), and for some yeasts.^' ^ Natu- 



82 S. A. Singal, V. P. Sydenstricker, and J. M. Littlejohn, /. Biol. Chem. 176, 1069 

 (1948). 



83 E. Bandier, Biochem. J. 33, 1130 (1939). 



8* H. Gounelle, Y. Raoul, and J. Marche, Compt. rend. 139, 30 (1945). 



1 B. C. J. G. Knight, Biochem. J. 31, 731, 966 (1937). 



2 J. H. Mueller, J. Biol. Chem. 120, 219 (1937). 



3 B. C. J. G. Knight, Vitamins and Hormones 3, 105 (1945). 



* W. H. Peterson and M. S. Peterson, Bacterial. Revs. 9, 49 (1945). 



5 A. S. Schultz, L. Atkin, and C. N. Frey, /. Am. Chem. Soc. 60, 1514 (1938). 



« P. R. Burkholder, I. McVeigh, and D. Moyer, /. Bacterial. 48, 385 (1944). 



