METABOLISM 



aneurine status. Normal adults were maintained for forty-four days 

 on a diet that provided 600 fig. of aneurine per 1000 cals., and the 

 following estimations were carried out : [a) the twenty-four-hourly ex- 

 cretion for the last four weeks of the period ; (b) the percentage 

 recovery of a 5-mg. oral test dose given at the end of the period ; 



(c) the recovery of a i-mg. intramuscular dose at the beginning, and 



(d) at the end, of the period. The twenty-four-hourly excretion was 

 found to be equivalent to 9 to 13 % of the intake, the recovery from 

 the 5-mg. dose to 15 to 22 % of the dose and from the two i-mg. 

 doses to 15 to 24 % and 8 to 21 % respectively. Each test in fact 

 gave a result that indicated a different nutritional status in the same 

 individual. E. Papageorge and G. T. Lewis ^^ compared the twenty- 

 four-hourly luinary output of aneurine in normal young adults with : 

 (a) the percentage recovery from a i-mg. oral test dose after four hours ; 

 and [b) the urinary output in a " fasting hour " specimen collected in 

 the hour immediately following the completion of a twenty-four- 

 hourly period and after an overnight fast. Satisfactory correlation 

 was obtained between the twenty-four-hour output on the one hand 

 and the " fasting hour " sample and the response to the i-mg. test 

 dose on the other, but the " fasting hour " test did not agree so well 

 with the response to the test dose. Nevertheless, the " fasting hour " 

 test was recommended as being the most convenient for nutritional 

 surveys. The excretion of less than 4 fig. in the " fasting hour " test 

 was regarded as indicative of aneurine deficiency. 



Possibly the most critical study of the test-dose method is that 

 carried out by Mickelsen et al.,^^ who made a statistical examination of 

 the values obtained for the aneurine excretion of groups of " normal " 

 young men. They showed that with dietary intakes of o-6, i-o, i-8 

 and 2-0 mg. of aneurine per day, the amount of aneurine (as deter- 

 mined by the thiochrome method) excreted in the urine was linearly 

 related to the intake, although one individual might excrete twice or 

 three times as much as another individual on the same diet. The 

 variations between individuals and groups increased with increased 

 excretion. These workers also studied the excretion of the pyrimidine 

 half of the aneurine molecule, which for brevity they term " pyramin ". 

 This was estimated by the yeast fermentation method of Schultz et al. 

 The excretion of pyramin was found to bear an exponential relation- 

 ship to the aneurine intake, a plateau being formed at high intakes 

 corresponding to an excretion of 400 fig. of pyramin per day. At 

 more normal levels, however, i.e. i to 2 mg. per day, the relationship 

 was linear. Moreover, the pyramin excretion was less variable than 

 the aneurine excretion, and statistical treatment was therefore easier. 

 The results suggest that insufficient attention has been given in the 

 past to the statistical significance of the values obtained in aneurine 



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