0000000000605769
AUTHOR
Olivier Loreau
Conjugated linoleic acid isomers in mitochondria
The beneficial effects exerted by low amounts of conjugated linoleic acids (C222222237) suggest that CLA are maximally conserved and raise the question about their mitochondrial oxidizability. Cis-9,trans-11-C18:2 (CLA1) and trans-10,cis-12-C18:2 (CLA2) were compared to cis-9,cis-12-C18:2 (linoleic acid; LA) and cis-9-C16:1 (palmitoleic acid; PA), as substrates for total fatty acid (FA) oxidation and for the enzymatic steps required for the entry of FA into rat liver mitochondria. Oxygen consumption rate was lowest when CLA1 was used as a substrate with that on CLA2 being intermediate between it and the respiration on LA and PA. The order of the radiolabeled FA oxidation rate was PA >> LA >…
In vivo oxydation of [9-14C] cyclic fatty acids derived from linoleic acid in the rat
International audience; Abstract - Heating oils and fats may lead to cyclization of polyunsaturated fatty acids, as for example linolenic acid. Cyclohexenyl and cyclopentenyl fatty acids are subsequently present in some edible oils and these are suspected to induce metabolic disorders. In a previous experiment using [1-14C] labeled molecules, we published that these cyclic fatty acids are beta oxidized to the same extent as linolenic acid, at least for the first cycle of beta oxidation. However, it is possible that the presence of a ring could alter the ability of the organism to fully oxidize the molecule. In order to test this hypothesis, we assessed the oxidative metabolism of cyclic fat…
Vaccenic and elaidic acid equally esterify into triacylglycerols, but differently into phospholipids of fed rat liver cells.
Elaidic acid (trans-9-C18:1 or trans-9) is assumed to exert atherogenic effects due to its double bond configuration. The possibility that trans-9 and vaccenic acid (trans-11-C18:1 or trans-11), its positional isomer, were biochemically equivalent and interchangeable compounds, was investigated by reference to their cis-isomers through esterification-related activities using rat liver cells and subcellular fractions. In hepatocytes, both trans-C18:1 were incorporated to the same extent in triacylglycerols, but trans-9 was more esterified than trans-11 into phospholipids (P < 0.05). Glycerol-3-phosphate acyltransferase activity in microsomes was lower with trans-11 than with trans-9, while t…