ANEURINE (thiamine) 



addition to aneurine a pyrimidine compound (see page io6), presumed 

 to be a metabolite, and the abnormaily high concentration of aneurine 

 in the leucocytes in leukemia is attributed to impaired utilisation of 

 the vitamin in this condition, since the amount of the pyrimidine 

 metabolite present was found to be substantially the same as in normal 

 individuals. 



The red cells of humans and rats contain 2-i and 1-4 /xg. of aneurine 

 pyrophosphate per 10^^ cells respectively and white cells 340 and 280 

 fig. per lo^i cells. ^^'^ 



Phosphorylation of Aneurine 



The phosphorylation of aneurine (see page 93) is extremely rapid,*° 

 intravenous administration of the hydrochloride into normal human 

 subjects being almost immediately followed by an increase in the 

 aneurine pyrophosphate content of the blood ; this fell to normal 

 again after about six minutes. Hepatic cirrhosis, but not nephritis, 

 impaired the phosphorylation of aneurine. Similarly, the intravenous 

 injection of cocarboxylase was followed by an increase in the plasma 

 and red cell aneurine diphosphate and free aneurine ; the level of the 

 latter rapidly returned to normal, but the diphosphate remained at 

 an abnormally high level for more than one hour. Patients with 

 advanced cirrhosis showed no immediate increase in the amount of 

 free aneurine in the blood, and exhibited a smaller rise in the diphos- 

 phate than that observed in normal subjects. 



Aneurine in Faeces 



The amount of aneurine excreted in the faeces by rats was constant, 

 whether the rats received o, 5 or 50 jug. of aneurine daily *^ but, in 

 deficient animals, the volume of faeces was greatly reduced ; the 

 aneurine was largely present in the form of cocarboxylase. The 

 faeces of aneurine-deficient rats did not alleviate s^miptoms of aneurine 

 deficiency when given to other rats. 



The amount of free aneurine excreted by humans on a synthetic 

 diet containing i mg. of aneurine per day or on a natural diet con- 

 taining 0-84 mg. was 13 to 17 and 25 to 49 /xg. respectively ; the com- 

 bined faecal aneurine was 2-4 to 5-1 times as high on the natural diet 

 as on the synthetic diet.*^ j^e faecal excretion of aneurine is rela- 

 tively constant, and independent of the dietary intake,*^, 44, 45 niost 

 of the aneurine in the faeces resulting from bacterial synthesis. *3» ** 

 It is present within the bacterial cells. 



Faecal excretion is discussed more fully on page 76. 



70 



