630 PANTOTHENIC ACID 



Several laboratories have used the chick assay to study the distribution 

 of pantothenic acid in a wide variety of foods, animal tissues, and feed- 

 stuffs.^' ^^"^^ (See the review on this subject by Jukes. ^^) However, some of 

 this work was done before the importance of the more recently discovered 

 vitamins was known, so that many of the values may be somewhat high. 

 Also, much of the older work was done with natural-type diets heated in 

 the dry state to destroy the pantothenic acid content. This heating process 

 undoubtedly affected other nutrients as well, some of which could not be 

 added back satisfactorily, 



3. Assays for Coenzyme A 



It is now possible to measure coenzyme A by in vitro methods from which 

 pantothenic acid values may be computed. Kaplan and Lipmann proposed 

 a method depending upon the reactivation by coenzyme A of an acetylating 

 system derived from pigeon liver extract.^" Assay values could be obtained 

 in a few hours. Various modifications of this method have since been 

 suggested. 



C. MICROBIOLOGICAL METHODS 



E. E. SNELL 



Pantothenic acid was discovered independently as a growth factor for 

 yeast^^ • ^^ and for lactic acid bacteria^* before its role in animal nutrition was 

 recognized. Following demonstration of its importance for animal life, repre- 

 sentatives of these two groups of organisms were used widely for its deter- 

 mination. 



The assay of this vitamin is complicated by its occurrence in bound forms, 



12 E. H. Hoag, H. P. Sarett, and V. H. Cheldelin, Ind. Eng. Chem. Anal. Ed. 17, 60 

 (1945). 



13 E. Willerton and H. W. Cromwell, Ind. Eng. Chem. Anal. Ed. 14, 603 (1942). 

 1^ T. H. Jukes, Biol. Symposia 12, 253 (1947). 



" M. E. Coates, J. E. Ford, G. F. Harrison, S. K. Kon, E. E. Shepheard, and F. W. 

 Wilby, Brit. J. Nutrition 6, 75 (1952). 



16 H. A. Waisman, O. Mickelsen, and C. A. Elvehjem, /. Nutrition 18, 247 (1939). 



" T. H. Jukes, J. Nutrition 21, 193 (1941). 



IS T. H. Jukes and S. Lepkovsky, /. Biol. Chem. 114, 117 (1936). 



1^ H. A. Waisman and C. A. Elvehjem, Vitamin Content of Meat. Burgess, Min- 

 neapolis, 1941. 



20 N. O. Kaplan and F. Lipmann, J. Biol. Chem. 174, 37 (1948). 



21 R. J. Williams, C. M. Lyman, G. H. Goodyear, and J. H. Truesdail, /. Am. Chem. 

 Soc. 54, 3462 (1932). 



22 R. J. Williams, Advances in Enzymol. 3, 257 (1943). 



23 E. E. Snell, F. M. Strong, and W. H. Peterson, Biochem. J. 31, 1789 (1937); /. Am. 

 Chem. Soc. QO, 2825 (1938). 



