IX. EFFKCTS OV DKFICIENCY 175 



ins rather than (hiring gestation and lactation only (Siea el alP). Under the 

 same coiulitions xanthopterin has only a small effect. "Lactation leuco- 

 penia" in rats on a purilied diet was found by Nelson el alP to be partially 

 prevented by addition of brewer's yeast or liver extract. Subsequently, 

 PG.V at a le\-el of I mg. per kilogram of diet was obserx'cd to increase 

 maternal weight and the total leucocytes and granulocytes although the 

 effect was not as complete as that produced by a liver fraction. ^^ In view 

 of subseciuent infoi-mation it seems probable that the additional improve- 

 ment noted with liver extract may have been due to its vitamin B12 con- 

 tent. The severity of the lactation leucopenia was increased and occasional 

 anemia was induced by addition of sulfasuxidine to a purified diet. Pteroyl- 

 glutamic acid was effective in preventing these symptoms.^^ 



2, Chicks 



A dietar}' deficiency of PGA is readily produced in chicks on purified 

 diets. Chicks appear to derive very little of their water-soluble vitamins by 

 intestinal synthesis and, in marked contrast to the rat, readily develop a 

 PGA deficiency by simple exclusion of this vitamin from the diet. 



Beginning in 1938 sc\'eral lines of investigation were initiated which led 

 to the recognition of PGA deficiency in chicks. Stokstad and Manning^® 

 found that chicks grew slowly on a diet composed primarily of polished 

 rice and water-washed fish meal and supplemented with sources of thiamine, 

 riboflavin, and pantothenic acid. Growth was increased by the addition of 

 yeast or alfalfa or their corresponding water extracts. This growth factor, 

 which was designated factor U, was adsorbed by fuller's earth and was stable 

 to autocla\'ing with acid and alkali. 



A macrocytic anemia and reduction of growth rate on a semipurified 

 type of diet were noted by Hogan and Parrott.-''' -* Growth was restored 

 and anemia prevented by inclusion of li\'er extract in the diet. Evidence 

 was presented to show that the anti-anemia principle was distinct from any 

 of the vitamins previously described, and the name ^'itamin Be was given 

 to this factor. A third group of investigators, Hutchings el al.,-^ presented 

 strong e\'idence that the "Norit eluate factor" required by Laclobacillus 



" A. J. Sica, A. M. Allgoier, and L. K. Cerecedo, Arch. Biochem. 18, 119 (194S). 



" M. M. Nelson, F. van Xouhuys, and H. M. Evans, Proc. Soc. Exptl. Biol. Med. 61, 



74 (1946). 

 =^ M. M. Xelson and H. M. Evans, Arch. Biochem. 13, 265 (1947). 

 " M. M. Nelson and H. M. Evans, Arch. Biochem. 18, 153 (1948). 

 " E. L. R. Stokstad and P. D. V. Manning, ./• Biol. Chim. 125, 6,S7 (1938). 

 " A. C!. Ilogan and E. M. Parrott, ,/. Biol. Chnn . 128, xlvi (1939). 

 2s A. C HoKaii and E. M. I'arrott , ./. Biol. ('hem. 132, 507 (1!)4()). 

 " B. L. Hutchings, X. Holionos, D. M. Ilegstcd, C. A. lllvohjom, and W. II. I'ctcr.son, 



./. Bii,l. Chrm. 140, 681 (1941). 



