The calorigenic action of thyroid extracts in normal infants was demonstrated in the preceding paper of this series.1 The increased expenditure of energy was shown to be due to an accelerated combustion of fat and of carbohydrate in proportions similar to those metabolized under basal conditions, as indicated by the constant levels of the respiratory quotients before and during treatment with the extracts. These results corroborate in part studies of adults2 showing that under the stimulus of an excess of thyroxine the body cells consume at an accelerated rate whatever type of food is brought them.
The preceding study, however, gave no information regarding the metabolism of protein, since the nitrogen elimination in the urine was not determined during calorimetric observations. This supplementary study of protein metabolism was therefore undertaken to make available complete data for determining the character of the intermediary metabolism of the essential foodstuffs in
WEYMULLER LE, WYATT TC, LEVINE SZ, KELLY M. THE RESPIRATORY METABOLISM IN INFANCY AND IN CHILDHOODXIV. THE EFFECT OF THYROID THERAPY ON THE METABOLISM OF PROTEIN IN NORMAL INFANTS. Am J Dis Child. 1932;43(6):1544–1551. doi:10.1001/archpedi.1932.01950070113009