656 PANTOTHENIC ACID 



associates,^" however, showed that the material was porphyrin in nature. 

 Chick and coworkers^^ tentatively identified it as protoporphyrin, but Mc- 

 Elroy et al.^° presented evidence for its identity with synthetic copropor- 

 phyrin I. The latter workers showed, also, by ablation experiments that the 

 source of the porphyrin was the Harderian glands. Figge and Atkinson^^ 

 reported that limitation of the drinking water of pantothenic acid-sup- 

 plemented rats led to a similar porphyrin deposition and concluded that 

 pantothenic acid may be involved in the regulation of water metabolism. 

 It has been pointed out by Smith^- that similar deposits had been observed 

 earlier in riboflavin deficiency and that they, also, had been attributed to 

 dehydration.^^ 



e. Growth Failure 



The effect of pantothenic acid concentrates (factor 2 concentrates) on 

 rat growth was clearly shown by Lepkovsky and coworkers®* in 1936. Their 

 sharp separation of factor 1 (pyridoxine) from factor 2 (pantothenic acid) 

 by adsorption of factor 1 on fuller's earth contributed greatly to progress 

 in the field of the B vitamins. Their conclusion that both factors were needed 

 for growth of rats was repeatedly confirmed in the following years with 

 concentrates of pantothenic acid®^"'^" and with the pure compound.^'^' 

 7. 31-42, 71-73 jj-^ j^rge mcasure the curtailment of growth in pantothenic acid 

 deficiency is due to inanition, but it has been shown by paired feeding ex- 

 periments that the administration of this vitamin results in a specific 

 growth-promoting effect not related to appetite.^* 



/. Dermatitis 



The first clear differentiation of the dermatitis of pantothenic acid de- 

 ficiency in the rat from that of other B-vitamin deficiencies appears to have 



«o L. W. McElroy, K. Salomon, F. H. J. Figge, and G. R. Cowgill, Science 94, 467 



(1941). 

 " F. H. J. Figge and W. B. Atkinson, Proc. Soc. Exptl. Biol. Med. 48, 112 (1941). 

 «2 S. G. Smith, Proc. Soc. Exptl. Biol. Med. 49, 691 (1942). 

 63 S. G. Smith and D. H. Sprunt, /. Nutrition 10, 481 (1935). 

 6* S. Lepkovsky, T. H. Jukes, and M. E. Krause, /. Biol. Chem. 115, 557 (1936). 

 68 C. E. Edgar and T. F. Macrae, Biochem. J. 31, 893 (1937). 



66 Y. SubbaRow and G. H. Hitchings, /. Am. Chem. Soc. 61, 1615 (1939). 



67 M. M. El-Sadr, H. G. Hind, T. F. Macrae, C. E. Work, B. Lythgoe, and A. R. 

 Todd, Nature 144, 73 (1939). 



68 G. H. Hitchings and Y. SubbaRow, /. Nutrition 18, 265 (1939). 



69 J. J. Oleson, D. W. Woolley, and C. A. Elvehjem, Proc. Soc. Exptl. Biol. Med. 42, 

 151 (1939). 



'0 D. W. Woolley, Science 91, 245 (1940). 



71 K. Unna, Ayn. J. Med. Sci. 200, 848 (1940). 



" K. Schwarz, Z. physiol. Chem. 275, 245 (1942). 



" K. Unna and G. V. Richards, J. Nutrition 23, 545 (1942). 



74 L. Voris, A. Black, R. W. Swift, and C. E. French, /. Nutrition 23, 555 (1942). 



