RIBOFLAVINE 



12. J. W. Czaczkes and K. Guggenheim, /. Biol. Chem., 1946, 162, 267. 



13. P. F. Fenton and G. R. Cowgill, /. Nutrition, 1947, 34, 273. 



14. R. L. Potter, A. E. Axelrod and C. A. Elvehjem, ibid., 1942, 24, 



449 ; H. Spector, A. R. Maass, L. Michaud, C. A. Elvehjem and 

 E. B. Hart, /. Biol. Chem., 1943, 150, 75. 



15. E. H. Hughes, /. Nutrition, 1940, 20, 233. 



16. P. B. Pearson, M. K. Sheybani and H. Schmidt, Arch. Biochem., 



1944, 3, 467. 



17. H, A. Waisman, Proc. Soc. Exp. Biol. Med., 1944, 55, 69 ; J. M. 



Cooperman, H. A. Waisman, K. B. McCall and C. A. Elvehjem, 

 /. Nutrition, 1945, 30, 45. 



18. W. Bolton, /. Agric. Sci., 1944, 34, 198. 



19. J. C. Fritz, W. Archer and D. Barker, Poultry Sci., 1939, 18, 449 ; 



D. M. Hegsted and R. L. Perry, /. Nutrition, 1948, 35, 411. 



20. S. H. Jackson, T. G. H. Drake, S. J. Shnger, E. V. Evans and R. 



Pocock, /. Nutrition, 1946, 32, 567. 



21. B. A. McLaren, E. Keller, D. J. O'Donnell and C. A. Elvehjem, 



Arch. Biochem., 1947. 15, 169. 



14. PHAR2V1ACOLOGICAL ACTION OF RIBOFLAVINE 



The toxicity and pharmacology of riboflavine were investigated by 

 K. Unna and J. G. Greslin,^ who found that the value of LD50 when 

 the vitamin was given intra-peritoneally into rats was 560 mg. per kg. 

 Death occurred in two to five days with anuria and azotemia, due to 

 obstruction of the kidneys by concretions. No toxic effects were 

 encountered with rats given 10 g. per kg. orally or with dogs given 

 2 g. per kg. orally. The daily oral administration of 10 mg. to rats 

 or of 25 mg. per kg. to dogs for four months gave rise to no toxic 

 symptoms. The metabolic, circulatory and respiratory systems and 

 isolated smooth muscles were not affected by riboflavine. 



R. Kuhn and P. Boul anger 2 recorded the toxicity of riboflavine to 

 mice by intraperitoneal injection as 340 mg. per kg. 



References to Section 14 



1. K. Unna and J. G. Greslin, J . Pharmacol., 1942, 76, 75. 



2. R. Kuhn and P. Boulanger, Z. physiol. Chem., 1936, 241, 233. 



15. FUNCTION OF RIBOFLAVINE 

 Presence in Enzymes 



Information concerning the function of riboflavine was available 

 long before anything was known as to its chemical nature, for in 1931 



190 



