The Fate of C14-Labeled Palmitic Acid Administered Intravenously as a Tripalmitin Emulsion.* †

Summary 1. In order to test the extent of utilization of fat emulsions in parenteral feeding, palmitic acid labeled with C14 at its sixth carbon was injected intravenously, in the form of the triglyceride, into fasted rats. 2. From 36 to 59% of the administered C14 was expired as CO2 in 24 hours. 3. Considerable amounts of the administered fatty acids were stored in adipose tissues throughout the body. 4. The availability of intravenously administered tripalmitin for metabolic purposes is further shown by the finding that as much as 78% of the radioactive fatty acids recovered from the liver and small intestine had been incorporated into phospholipids.