The Synthesis of Fatty Acids by Rat Liver Slices in Tritiated Water

Abstract

Long chain fatty acids from rat liver slices were isolated after incubation in a medium enriched with tritiated water. The saturated fatty acids were separated by lead salt precipitation and the incorporation of radioactivity into the individual acids determined. The major portion of radioactivity was found in palmitic and stearic acids. Sequential degradation of the saturated fatty acids was carried out and the intramolecular location of tritium determined. Contrary to expectation, more tritium was found in the odd-numbered carbon atoms than the even-numbered. It is suggested that an exchange reaction between reduced triphosphopyridine nucleotide and water occurs before or during fatty acid synthesis, and that the exchange is essentially complete. (auth)