A comparison of the metabolism of elaidic, oleic, palmitic, and stearic acids in the rat

A comparison has been made of the metabolism of 1-C14-labeled oleic, elaidic, palmitic, and stearic acids in the rat. Each acid was fed as a component of randomly rearranged soybean oil. All the acids were more than 96% absorbed. The rate of catabolism and the extent to which elaidic acid was excreted in the respiratory CO2 were essentially the same as those of oleic acid and both of these acids were similar to palmitic acid. Oleic, elaidic, and palmitic acids were catabolized to CO2 to a greater extent than was stearic acid. Elaidic acid seemed to be incorporated into the lymph phospholipids to a slightly greater extent than was oleic acid during the peak of absorption; otherwise, elaidic acid was similar to oleic acid in its absorption and distribution among the lymph lipids. Stearic acid was incorporated into the lymph phospholipids to a considerably greater degree (~8%) than were the other acids (~2–3%). The major transport of each fatty acid was via the lymph glycerides, being ~90% for stearic acid and ~97% for the other acids.