On the quantitative importance of omega-oxidation of fatty acids.

The relative importance of omega-oxidation of fatty acids in livers of starved rats was studied by determination of the ratio between 14C at C1 and at C2, C3, C4 in acetoacetate formed from [16-14C]palmitic acid in vivo and in vitro and from [10(-14)C]decanoic acid in vitro. The results are consistent with the possibility that at least a small fraction of the fatty acids may be subject to primary omega-oxidation prior to beta-oxidation in the ketotic state. The maximal figure for this pathway was calculated to be of the magnitude 5--10%. The metabolic consequences of a pathway involving primary omega-oxidation of fatty acids are discussed.