The metabolism ofTrans, trans‐octadecadienoic acid. Incorporation ofTrans, trans‐octadecadienoic acid into the C20 polyunsaturated acids of the rat

Trans,trans‐9,12‐octadecadienoic acid‐1‐C14 was fed to adult rats. After four hr the animals were killed and the fatty acids isolated from their organ lipids. The 20‐carbon fatty acids were isolated and degraded stepwise. Radioactivity of the degradation products indicated that the fed acid was incorporated into the isolated C20 acids, mainly eicosatetraenoic acid probably with twotrans‐double bonds, while radio‐activity throughout the chain gave evidence for a synthesis of eicosatrienoic and eicosatetraenoic acid from acetate derived from the fed material. In a separate experiment, unlabeledtrans,trans‐9,12‐octadecadienoic acid was fed to wealing rats for 14 days. Isolation of their fatty acids also gave evidence for the incorporation of the fed acid into eicosatrienoic and eicosatetraenoic acids containingtrans double bonds.