IX. KFFKCTS OF DEFICIENCY 180 



These results show that the pig requires both \itamiii Bi_> and P(1A. The 

 basic requirement for blot)(l cell formation seems to be that of P(1A, but 

 in some cases of double ileficiency either one may provoke a response. Con- 

 tinued administration of vitamin B12 does not give complete protection 

 against anemia whereas contiiuied administration of PCiA apparently does. 

 The growth-stimulating function of vitamin B12 cannot be substituted by 

 PGA. 



5. Mice 



Evidence has been obtained that mice require PGA for growth and re- 

 production. Xielsen and Black*'^ observed that mice grown on a purified 

 tliet containing sulfasuxidine give a growth response to folic acid concen- 

 trates prepared from lixer extract. The extent of the deficiency was less 

 when the sulfonamide was omitted from the diet. Cerecedo and Mirone^^ 

 investigated the nutritive re(iuirements of lactation and found that addition 

 of 10 mg. of PGA per kilogram of a purified diet doubled the average num- 

 l)er of mice weaned and increased the weight gain of the lactating mother. 

 Xo significant effect on litter size was observed. 



6. Guinea Pigs 



A series of studies with guinea pigs on purified diets indicated that three 

 unidentified dietary factors are required, two of which were found present 

 in linseed oil meal. It was later shown by WooUey and Sprince that PGA 

 could replace one of the factors.^^ The deficiency was characterized by 

 lethargy, salivation, loss in weight, terminal convulsions, and death. 



7. Mink 



The effects of pterolyglutamic acid deficiency in mink have been studied 

 by Schaefer et al}^ This was characterized by loss of body weight, diarrhea, 

 anorexia and leucopenia. The deficiency symptoms were rapidly corrected 

 by administration of pteroylglutamic acid. Some evidence was obtained 

 which indicated that an unidentified factor in liver was also needed.^^ 



8. Dogs 



Dogs are very refractory to pteroylglutamic acid deficiency. Michaud 

 et al.^ found that a purified ration supplemented with the water-soluble 

 vitamins will support excellent growth even in the jiresence of 4% sulfa- 



" K. Nielsen iirid A. Black, /. Nutrition 28, 203 (1944). 



** L. R. Cerecedo and L. Mirone, Arch. Biochem. 12, 154 (1947). 



ss D. W. WooIIey and H. Sprince, ./. Biol. Chcm. 157, 447 (1945). 



»« .\. E. Schaefer, C. K. Whitehair, and C. A. Klvehjem, Proc. Soc. Es/ill. Biol. M(<l. 



62, 169 (1946). 

 " L. Michaud, A. R. Maass, W. W. RiK'tianior, and ('. A. I'.lvolijeni, I'ruc. Soc. Espll. 



Biol. Med. 56, 148 (1944). 



