ANEURINE (thiamine) 



fact, demonstrated by T. Suzuki and A. Takamatsu/^ who showed 

 that it was methylglyoxal and that the administration of vitamin B^ 

 diminished the methylglyoxal content of the milk. R. Orimo ^"^ 

 showed that the milk of vitamin Bi-deficient women was low in gly- 

 oxalase, the concentration of which could, however, be raised by 

 giving the vitamin, whilst A. Takamatsu and A. Sato ^^ showed that 

 methylglyoxal induced pathological changes in rabbits similar to those 

 in infantile beriberi. 



J. Vogt-Moller ^^ suggested that the symptoms of beriberi were due 

 to poisoning by methylglyoxal which accumulated as the result of 

 some breakdown in the action of the enzyme glyoxalase or its coenzyme, 

 glutathione (glutamyl-cysteyl-glycine) ; he favoured the latter alter- 

 native. B. S. Piatt and G. D. Lu,^^ however, could find no evidence 

 that methylglyoxal was responsible for the symptoms of beriberi. 



Unfortunately, it appears never to have been decided whether the 

 cure of infantile beriberi was due to the administration of vitamin B^ 

 or to administration of glutathione, as no information is available as 

 to the nature of the vitamin B supplements used. In many instances 

 these were probably concentrates prepared from liver or yeast and 

 therefore likely to contain both. 



There is no real proof that aneurine deficiency leads to an accumu- 

 lation of methylglyoxal, although there is convincing evidence that 

 methylglyoxal is responsible for infantile beriberi. In the light of 

 present knowledge, however, this is just as likely to be produced by a 

 deficiency of glutathione as of aneurine. 



Experiments on the Respiration of Brain Tissue 



The explanation of the relationship between vitamin B^ deficiency 

 and the accumulation of lactic or pyruvic acid in the blood was dis- 

 covered by R. A. Peters, 2^ who, in a paper of fundamental importance, 

 showed that normal pigeon brain slices in Ringer phosphate solution 

 containing glucose as substrate had a higher oxygen uptake than 

 avitaminous brain slices. The same results were obtained when 

 sodium lactate or sodium pyruvate were used as substrates. When 

 aneurine was added to the solutions, the oxygen uptake of the avit- 

 aminous tissue was raised to the normal value in all three instances. 

 The reaction was extremely sensitive and highly specific. It was 

 described as the catatorulin effect, and was made the basis of a method 

 of assaying vitamin B^ (see page 28). Peters was able to show also 

 that, with sodium succinate as substrate, normal and avitaminous 

 brain tissue respired at the same rate, and he therefore concluded 

 that the vitamin was concerned with the oxidation of pyruvic acid, 

 but not of succinic acid. 



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