38 P-AMINOBENZOIC ACID 



tritioiial achromotrichia.^^''''' It should be mentioned, however, that Wil- 

 Hams'^' was unable to show any effect of pantothenic acid on gray hair in 

 rats, and Frost et alP were able to protect only a small percentage of their 

 rats against achromotrichia with pantothenic acid alone, whereas liver con- 

 centrates were much more effective. 



Martin''^ in further studies produced evidence that PABA is essential for 

 growth and prevention of achromotrichia in the rat only when inositol is 

 present in the diet. Conversely, the presence of PABA was reported to pro- 

 voke a need for inositol. Thus the six B vitamins — thiamine, riboflavin, 

 pyridoxine, choline, nicotinic acid, and calcium pantothenate — or these six 

 plus PABA and inositol afford normal nutrition, but the omission of either 

 one of the last two factors induces a requirement for the other. 



The forementioned findings of Ansbacher and Martin with respect to the 

 significance of PABA in animal nutrition instigated one of the most pro- 

 longed polemics in the nutrition field. Thus Unna et al.,''^ Emerson, '^^ and 

 Henderson et al?^ confirmed the activity of pantothenic acid as an achromo- 

 trichial factor and reported only negative results from their studies with 

 PABA. Ershoff" failed to confirm Martin'^^ by showing that no adverse 

 effects in rats are encountered when either PABA or inositol alone is incor- 

 porated in their diet. On the other hand, a number of investigators have 

 reported beneficial effects from the feeding of PABA. Sure^^'^ reported 

 that, on a purified diet containing thiamine, riboflavin, pyridoxine, choline, 

 calcium pantothenate, nicotinic acid, and factor W concentrate from fiver 

 extract, female rats are unable to nurse their young. When the diet is sup- 

 plemented further with PABA and inositol most of the young born to 

 mothers consuming the supplemented diet are raised successfully. Cfimenko 

 and McChesney^" confirmed the essential nature of inositol for lactation 



6« P. Gyorgy and C. E. Poling, Science 92, 202 (1940). 



«^ K. Unna and W. L. Sampson, Proc. Soc. Exptl. Biol. Med. 45, 309 (1940). 



68 G. A. Emerson and H. M. Evans, Proc. Soc. Expil. Biol. Med. 46, 655 (1941). 



«i'K. Unna, Am. J. Physiol. 133, 473 (1941). 



'0 C. A. Elvehjem, L. M. Henderson, S. Black, and E. Nielsen, J Biol. Chcm. 140, 



xxxvi (1941). 

 " R. R. Williams, Science 92, 561 (1940). 

 ^2 D. V. Frost, R. C. Moore, and F. P. Dann, Proc. Soc. Expil. Biol. Med. 46, 507 



(1941). 



73 G. J. Martin, A7n. J. Physiol. 136, 124 (1942). 



74 K. Unna, G. V. Richards, and W. L. Sampson, /. Nutrition 22, 553 (1941). 

 78 G. A. Emerson, Proc. Soc. Exptl. Biol. Med. 47, 448 (1941). 



76 L. M. Henderson, J. M. Mclntire, H. A. Waisman, and C. A. Elvehjem, ./. Niiiri- 

 lion 23, 47 (1942). 



77 B. H. Ershoff, Proc. Soc. Exptl. Biol. Med. 56, 190 (1944). 



78 B. Sure, Science 94, 107 (1941). 



79 B. Sure, /. Nutrition 26, 275 (1943). 



80 D. R. Climenko and E. W. McChesney, Proc. Soc. Expil. Biol. Med. 51, 157 (1942). 



