THE FOLIC ACID COMPLEX 



51. F. E. King, p. C. Spensley and R. H. Nimmo-Smith, Nature, 1948, 



162, 153 ; F. E. King, R. M. Acheson and P. C. Spensley, /. 

 Chem. Soc, 1949, 1401. 



52. H, S. Forrest and J. Walker, ibid., 2002 ; M. Viscontini and J. 



Meier, Helv. Chim. Acta, 1949, 32, 877 ; R. Gavard and M. 

 Viscontini, ibid., 2.^2^1. 



53. E. Woll, Trans. N.Y. Acad Sci., 1948, 10, 83. 



54. P. A. Little, A. Sampath, V. Paganelli, E. Locke and Y. SubbaRow, 



ibid., 83 ; P. A. Little, A. Sampath and Y. SubbaRow, /. Lab. 

 Clin. Med., 1948, 33, 1144. 



55. D. R. Weir, A. D. Welch and R. W. Heinle, Proc. Soc. Exp. Biol. 



Med., 1949, 71, 107. 



56. J. H. Burchenal, S. F. Johnston, J. R. Burchenal, M. N. Kushida, 



E. Robinson and C. C. Stock, ibid., 381. 



57. J. H. Burchenal, M. N. Kushida, S. F. Johnston and M. A. Cremer, 



ibid., 559. 



58. J. M. Stickney, A. B. Hagedorn, S. D. Mills and T. Cooper, /. Lab. 



Clin. Med., 1948, 33, 148 1 ; W. Jacobson, W. C. Levin and 

 G. Holt, ibid., 1641 ; M. Pierce and H. Alt, ibid., 1642 ; L. 

 Berman, A. R. Axelrod, E. C. VonderHeide and E. A. Sharp, 

 ibid., 1643 ; S. G. Taylor, D. Slaughter, F. W. Preston, J. 

 Crumrine and G. Hass, ibid., 1643 ; S. Farber, L. K. Diamond, 

 R. D. Mercer, R. F. Sylvester, and J. A. Wolff, New England J. 

 Med., 1948, 238, 787 ; L. M. Meyer, H. Fink and A. Sawitsky, 

 Amer. J. Clin. Path., 1949, 29, 119 ; P. L- de V. Hart, Brit. Med. 

 J., 1949, 2, 363. 



59. R. S. de Ropp, Nature, 1949, 164, 954. 



19. FUNCTION OF FOLIC ACID 



In animals and man, folic acid is necessary for the proper function- 

 ing of the haemopoietic system. Nutritional anaemias are due to the 

 absence of free or combined folic acid from the diet, whilst pernicious 

 anaemia is probably due to an inability to utilise combined folic acid, 

 owing to the absence of vitamin B12 from the liver (see page 498). 



No satisfactory suggestion has yet been put forward to explain 

 the mechanism whereby pteroylglutamic acid stimulates reticulo- 

 cytosis, nor is it known why it is essential for the growth of bacteria. 

 According to J. E. Davis ^ the action of folic acid is mediated through 

 choline esterase. He claimed that subcutaneous injection of acetyl- 

 choline produced hyperchromic anaemia in dogs and that both liver 

 extract and folic acid increased the number of reticulocytes and 

 red blood cells, at the same time increasing the choline esterase activity. 

 The choline esterase activity of dog serum was increased in vitro by 

 incubation with folic acid or liver extract, and oral administration of 

 folic acid to normal humans also increased the choline esterase activity. 



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