Oxidation and esterification of geometrical and positional isomers of octadecenoic acids in perfused rat liver.
The metabolic fate of the geometrical isomers of 6-, 9-, and 11-octadecenoic acids was studied in isolated perfused rat livers. Although the ketogenicities of these monounsaturated fatty acids generally decreased as the double bond was moved away from the carboxyl group, a dependence on the geometrical difference was found only for 9-octadecenoate, the rate being significantly lower in the cis-isomer. Very low density lipoprotein lipid secretion was distinctly and specifically decreased when trans-9-octadecenoic acid was perfused, but no such difference was observed with other isomers. Various trans-isomers were actively incorporated into the hepatic lipids and secreted apparently at the expense of preexisting endogenous cis-octadecenoate. The trans-isomers were all incorporated exclusively at the 1-position of hepatic phosphatidylcholine. Concentrations of the cis-octadecenoate in the glycerolipids secreted and remaining in the liver were characteristically modified depending on the location of the ethylenic bond of the cis-octadecenoate. Thus, both the location of the double bond in the acyl-chain and the geometrical configuration specifically influence the rate of oxidation and esterification of octadecenoic acid in perfused rat liver.
D000818:Animals; D001665:Binding Sites; D004951:Esterification; D007536:Isomerism; D008099:Liver / Q000378:metabolism*; D008297:Male; D009829:Oleic Acids / Q000378:metabolism*; D010084:Oxidation-Reduction; D010477:Perfusion; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013237:Stereoisomerism
D009829:Oleic Acids; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines