Conversion of 15th Carbon of Palmitic Acid to C0 2 by the Intact Rat. ∗

Abstract

Summary

1. Palmitic acid labeled with C¹⁴ in its 15th carbon atom was injected intravenously, in the form of its triglyceride, into fasted rats, and the expired C0₂ was collected at various time intervals. 2. The amounts of C¹⁴O₂ expired and the specific activity-time relationships of the expired C0₂ after the injection of tripalmitin-15-C¹⁴ correspond closely to the results reported previously with tripalmitin-1-C¹⁴, tripalmitin-6-C¹⁴, and tri-palmitin-11-C¹⁴. Our present findings thus support our previous postulate that the fasted intact rat, in contrast to certain isolated tissue preparations, converts all carbon atoms of palmitic acid to C0₂ at practically identical rates. 3. Possible explanations which may account for the differences observed between intact animals and isolated liver preparations are examined.