title: Effects of clofibrate feeding on essential fatty acid desaturation and oxidation in isolated rat liver cells.
abstract: The effects of clofibrate feeding on the metabolism of polyunsaturated fatty acids were studied in isolated rat hepatocytes. Administration of clofibrate stimulated the oxidation and particularly the peroxisomal beta-oxidation of all the fatty acids used. The increase in oxidation products was markedly higher when n-3 fatty acids were used as substrate, indicating that peroxisomes contribute more to the oxidation of n-3 than n-6 fatty acids. The whole increase in oxidation could be accounted for by a corresponding decrease in acylation in triacylglycerol while the esterification in phospholipids remained unchanged. A marked stimulation of the amounts of newly synthesized C16 and C18 fatty acids recovered, was observed when 18:2(n-6), 20:3(n-6), 18:3 (n-3) and 20:5(n-3), but not when 20:4(n-6) and 22:4(n-6) were used as substrate. This agrees with the view that extra-mitochondrial acetyl-CoA produced from peroxisomal beta-oxidation is more easily used for fatty acid new synthesis than acetyl-CoA from mitochondrial beta-oxidation. The delta 6 and delta 5 desaturase activities were distinctly higher in cells from clofibrate fed rats indicating a stimulating effect.
authors.affiliation: Institute for Clinical Biochemistry, University of Oslo, Norway.
authors.forename: M
authors.initials: M
authors.lastname: Grønn
authors.forename: E
authors.initials: E
authors.lastname: Christensen
authors.forename: T A
authors.initials: TA
authors.lastname: Hagve
authors.forename: B O
authors.initials: BO
authors.lastname: Christophersen
mesh_terms: D000818:Animals; D002994:Clofibrate / Q000494:pharmacology*; D000090943:Delta-5 Fatty Acid Desaturase; D004041:Dietary Fats / Q000494:pharmacology; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D050602:Linoleoyl-CoA Desaturase; D015227:Lipid Peroxidation / Q000187:drug effects*; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000090943:Delta-5 Fatty Acid Desaturase; D004041:Dietary Fats; D005231:Fatty Acids, Unsaturated; D044943:Fatty Acid Desaturases; D050602:Linoleoyl-CoA Desaturase; D002994:Clofibrate