Human Respiratory Quotients in Relation to Alveolar Carbon Dioxide and Blood Lactic Acid After Ingestion of Glucose, Fructose, or Galactose

Publisher Website
Google Scholar
Abstract
The effects of the ingestion of 50, 75, or 100 gm. of glucose, fructose, or galactose on the alveolar carbon dioxide, the blood lactic acid, and the respiratory quotient were studied over a period of 4 hours with two normal men. In comparison with control experiments, the alveolar carbon dioxide showed a significant change (decrease) only in the galactose experiments. The blood lactic acid increased after all three sugars, the increase being most marked and lasting longest after fructose. The respiratory exchange measurements were corrected for the effects of these changes in blood lactic acid and alveolar carbon dioxide, and the resultant net increases in the respiratory quotients ascribable to the ingestion of the sugars were calculated. After glucose the maximum net increase in quotient occurred within 90 to 135 minutes, and there was no return to the pre-ingestion level in 4 hours. After galactose the net increases were about the same as after glucose. The greatest net increases in the respiratory quotient were produced by the ingestion of fructose. The differences in the rises in quotient indicate differences in the rapidity of combustion of the sugar or differences in the rate at which sugars may be transformed into fat.