Metabolism of Lactic Acid and Glycerol in C 14 -Glyceryl Lactopalmitate. ∗

Summary

1. The fate of lactic acid-2-C¹⁴ following administration of glyceryl lacto-2-C¹⁴-palmitate was studied by converting lactate from blood or lymph to acetaldehyde which was counted as the dimedon derivative and as 2,2,7,7,9-pentamethyl-4,5-dioxo-octahydroxanthene. 2. The lactic acid content of lymph samples from the thoracic duct of the dog is subject to variation which arises from the speed with which samples are obtained through a cannula. 3. Appearance of radioactive CO₂ in the expired air of rats following the administration of glyceryl lacto-2-C¹⁴-palmitate or glyceryl-1,3-C¹⁴-lactopalmitate, as well as the low fecal radioactivities, indicates a high degree of utilization of the fat. 4. In comparison with glycerol and glyceryl esters the metabolism of glyceryl-1-3-C¹⁴-lactopalmitate, as determined by the radioactivity of expired CO₂, follows a path consistent with that expected from a normal ester of glycerol.