Metabolism of essential fatty acids. IV. Incorporation of linoleate into arachidonic acid.

It has recently been demonstrated in this laboratory (1) that arachidonic acid is formed in the body from acetate and a Cl8 precursor and that, under the conditions of the experiment, linoleic acid is not synthesized from acetate. Spectrophotometric evidence (2, 3) has indicated that administration of linoleate to animals results in an increase in tetraene of the arachidonate type (as measured by alkali isomerization). The experiments reported in this paper were designed to test the hypothesis that the exogenous Cl8 precursor is linoleic acid and that the linoleate molecule is incorporated in its entirety into arachidonate.