Double bond position affects metabolism of cis-Octadecenoates.

The metabolic fate of cis-positional isomers of octadecenoates has been compared to that of naturally occurring oleic acid (cis-delta9). Radioactive mixtures of tritium-labeled positional octadecenoate isomer and oleic acid-10(-14)C 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 of cis-positional isomers delta8 through delta12. Incorporation into egg lipid fractions is as follows: triglycerides: delta9 greater than delta8, delta9 greater than delta10, delta9 greater than delta11, delta9 greater than 12; phospholipid: delta9 greater than delta8, delta9 greater than delta10, delta9 less than delta11, delta9 less than delta12.