title: Modification of odd-chain length unsaturated fatty acids by hepatocytes of rainbow trout (Oncorhynchus mykiss) fed diets containing fish oil or olive oil.
abstract: Hepatocytes isolated from rainbow trout fed on diets containing either fish oil or olive oil were incubated with individual odd-chain length unsaturated fatty acids (19:1n-9, 19:2n-6, 19:3n-3, 21:2n-6, 21:3n-6, 21:4n-6, 21:3n-3, and 21:5n-3) to examine whether these fatty acids were substrates for modification by desaturation and elongation. All odd-chain length fatty acids were readily assimilated into the lipids of hepatocytes from both dietary groups of fish, but their conversion to longer-chain, more unsaturated derivatives was more pronounced with cells from trout fed olive oil. Thus, the conversion of 19:2n-6 and 21:2n-6 to 21:3n-6 and 21:4n-6, and of 19:3n-3 to 21:4n-3 and 21:5n-3, was most obvious in cells from the olive oil group, as was the conversion of 21:3n-6 and 21:3n-3 to 21:4n-6 and 21:4n-3, respectively. Elongation of 19:1n-9 to 21:1n-9 and 23:1n-9 occurred in cells from both groups. No 23:6n-3 was detectable as a product of 19:3n-3 or 21:3n-3. However, this fatty acid was a major product formed by cells from fish fed olive oil presented with 21:5n-3. Cells from both groups of fish incorporated 21:4n-6 and 21:5n-3 into their lipids largely without modification but chain-shortened around 40, 23, and 19% of the incorporated 21:2n-6, 21:3n-3, and 19:1n-9, respectively. The results demonstrate that odd-chain length unsaturated fatty acids can act as substrates for the desaturation, elongation, and chain-shortening systems of trout hepatocytes.
authors.affiliation: N.E.R.C. Unit of Aquatic Biochemistry, Department of Biological and Molecular Sciences, University of Stirling, Scotland, United Kingdom. covarodr@ull.es
authors.forename: C
authors.initials: C
authors.lastname: Rodríguez
authors.forename: R J
authors.initials: RJ
authors.lastname: Henderson
authors.forename: A E
authors.initials: AE
authors.lastname: Porter
authors.forename: J R
authors.initials: JR
authors.lastname: Dick
mesh_terms: D000818:Animals; D004032:Diet; D005227:Fatty Acids / Q000032:analysis; D015525:Fatty Acids, Omega-3 / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D005395:Fish Oils / Q000494:pharmacology*; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D000069463:Olive Oil; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D010938:Plant Oils / Q000494:pharmacology*
chemical_list: D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D008055:Lipids; D000069463:Olive Oil; D010938:Plant Oils