Abstract
The metabolic fate ofcis‐positional isomers of octadecenoates has been compared to that of naturally occurring oleic acid (cis‐Δ9). Radioactive mixtures of tritium‐labeled positional octadecenoate isomer and oleic acid‐10‐14C were administered to laying hens, and their eggs were analyzed for the isotopic ratios (3H/14C) incorporated into total egg lipid, triglycerides, and phospholipids. Variations in the isotopic ratios indicated the comparative metabolic utilization ofcis‐positional isomers Δ8 through Δ12. Incorporation into egg lipid fractions is as follows: triglycerides: Δ9>Δ8, Δ9>Δ10, Δ9>Δ11, Δ9>12; phospholipid: Δ9>Δ8, Δ9>Δ10, Δ9<Δ11, Δ9<Δ12.