THE FOLIC ACID COMPLEX 



growth factors necessary for chicks ; since then vitamin B^g has been 

 recognised to be such a factor (page 530). 



In addition to its other effects, synthetic pteroylglutamic acid 

 cured a perosis in chicks resulting from the feeding of a diet adequate 

 in choline (page 590), biotin and manganese. ^^ The condition was 

 rendered more severe by sulphasuxidine, and it was therefore suggested 

 that the effect was due to the folic acid stimulating the growth of 

 intestinal bacteria, which in turn synthesised the antiperotic factor. 



Pteroyl glutamic acid was also a chromotrichial factor for the 

 chick.i2 



A biological property of folic acid apparently unconnected with 

 the phenomena so far discussed is one concerned with the action of 

 stilboestrol on the oviducts of chicks. Normally, the weight of these 

 organs is increased on administration of the oestrogen, but this did 

 not occur in folic acid-deficient chicks, although pantothenic acid- 

 deiicient birds behaved normally. Administration of the L. casei 

 factor resulted in the response becoming normal. The response to 

 stilboestrol was also reduced when chicks maintained on an adequate 

 diet were given the folic acid antagonist, 7-methyl-folic acid (page 

 519), and the inhibition was reversed by folic acid.^' 



No nerve lesions were observed in folic acid-deficient chicks.^® 

 Folic acid-deficient chicks gave a response to some other factors 

 besides the recognised members of the folic acid complex. Thus, an 

 increase in growth, feathering and haemoglobin formation was observed 

 with preparations of vitamins B^o and B^,^^ the precise nature of 

 which is not yet known (page 614). 



Similarly, the growth and haemoglobin response of chicks to factor 

 R could not be accounted for by the amount of preformed folic acid 

 in the preparation. The folic acid content was, however, increased 

 by incubation with chick liver, rat liver or hog kidney,^^ the last- 

 named being the most effective and liberating folic acid in amounts 

 sufficient to account for the response obtained with chicks. It was 

 therefore concluded that factor R was a mixture of folic acid con- 

 jugates. The response to factor R was not affected by succinyl 

 sulphathiazole. 



Turkeys 



On a vitamin Bc-deficient diet, turkey poults developed a spastic 

 cervical paralysis, ^^ which terminated in death within twenty-four to 

 thirty-six hours. In addition, growth was delayed, and a moderate 

 degree of anaemia developed, the erythrocytes being larger in diameter, 

 with less dense and larger nuclei.22 Pteroylglutamic acid or the 

 triglutamate were equally effective in curing the symptoms. 22« 



486 



