654 PENTOTHENIC ACID 



finding was confirmed by others using concentrates,""^^ impure pantothenic 

 acid,^" and finally the pure compound. ^^'" Considerable controversy de- 

 veloped, however, as to how completely the achromotrichia of filtrate factor 

 deficiency (i.e., factors not adsorbed on fuller's earth and known to be differ- 

 ent from thiamine, riboflavin, and pyridoxine) could be prevented or cured 

 by pantothenic acid. Williams^^ reported completely negative results, and 

 Frost et al?^ found only a slight effect of the pure vitamin in preventing 

 graying in their animals. Dimick and Lepp*" reported that some measure 

 of graying persisted in rats given 50 7 of synthetic pantothenic acid daily, 

 and Gyorgy and Poling^^ indicated that depigmentation of a less striking 

 nature reappeared in their animals which had been cured of graying even 

 though pantothenic acid supplementation was continued. Emerson and 

 Evans^^ and Pavcek and Baum*^ stated that pantothenic acid, although 

 quite effective, did not restore the hair of rats to its original color but re- 

 sulted in stippling. Despite the occasional negative findings and the incom- 

 plete repigmentation frequently observed, it is generally conceded that 

 pantothenic acid is an important factor in the prevention or treatment of 

 dietary achromotrichia. It is also recognized that under appropriate experi- 

 mental conditions other dietary deficiencies may be involved. The effect 

 of a copper deficiency on graying of the hair in rats is well established ."^^"^^ 



27 J. J. Oleson, C. A. Elvehjem, and E. B. Hart, Proc. Soc. Exptl. Biol. Med. 42, 283 

 (1939). 



28 A. Mohammad, O. H. Emerson, G. A. Emerson, and H. M. Evans, J. Biol. Chem. 

 133, 17 (1940). 



29 H. Chick, T. F. Macrae, and A. N. Worden, Biochem. J. 34, 580 (1940). 



30 P. Gyorgy, C. E. Poling, and Y. SubbaRow, /. Biol. Chem. 132, 789 (1940). 



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



32 P. Gyorgy and C. E. Poling, Proc. Soc. Exptl. Biol. Med. 45, 773 (1940). 



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

 3^ K. Unna, Am. J. Physiol. 133, 473 (1941). 



3s C. A. Elvehjem, L. M. Henderson, S. Black, and E. Nielsen, /. Biol. Chem. 140 

 xxxvi (1941). 



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



37 L. M. Henderson, J. M. Mclntire, H. A. Waisman, and C. A. Elvehjem, J. Nutri- 

 tion 23, 47 (1942). 



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



39 D. V. Frost, R. C. Moore, and F. P. Dann, Proc. Soc. Exptl. Biol. Med. 46, 507 

 (1941). 



^0 M. K. Dimick and A. Lapp, /. Nutrition 20, 413 (1940). 



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

 « P. L. Pavcek and H. M. Baum, Proc. Soc. Exptl. Biol. Med. 47, 271 (1941). 

 « H. L. Keil and V. E. Nelson, J. Biol. Chem. 93, 49 (1931). 

 " A. H. Free, Proc. Soc. Exptl. Biol. Med. 44, 371 (1940). 

 « J. M. Hundley, Proc. Soc. Exptl. Biol. Med. 74, 531 (1950). 



46 J. M. Hundley and R. B. Ing, Endocrinologij 48-, 482 (1951); J. M. Hundley and R. 

 B. Ing, Federation Proc. 10, 385 (1951) 



