title: Accumulation and apparent oxidation of cis,trans-18 : 2 isomers relative to linoleic acid in rats.
abstract: Dietary cis,trans-18 : 2 isomers impair desaturation and elongation of linoleic acid (Delta9cis,12cis-18 : 2), but little is known of their proportional partitioning between accumulation and oxidation. The present study was therefore designed to assess the accumulation and apparent oxidation of cis,trans-18 : 2 isomers compared with that of trans-18 : 1 isomers and Delta9cis,12cis-18 : 2 in rats. Accumulation is defined as whole-body increase in a fatty acid during a given period (i.e. final body content-initial body content). The apparent oxidation (disappearance) is defined as whole-body utilization of a fatty acid relative to its intake for a given period (intake-excretion-accumulation-longer-chain products)/intakex100). The animals were fed on a diet containing 15 % (w/w) partially hydrogenated rapeseed oil with 1.72 % energy as cis,trans-18 : 2 isomers and varying amounts of Delta9cis,12cis-18 : 2. The apparent oxidation of total cis,trans-18 : 2 isomers (72-76 % dietary intake) was greater than that of Delta9cis,12cis-18 : 2 (38-51 % dietary intake) but it was similar to that of total trans-18 : 1 isomers (78-82 % dietary intake). Among the four isomers, the apparent oxidation of Delta9trans,12trans-18 : 2 was greater than that of the other isomers including Delta9trans,12cis-18 : 2, Delta9cis,12trans-18 : 2 and Delta9cis,13trans-18 : 2. Accumulation of Delta5cis,8cis,11cis,15trans-20 : 4 and Delta5cis,8cis,11cis,14trans-20 : 4 derived from chain-elongation and desaturation of Delta9cis,13trans-18 : 2 and Delta9cis,12trans-18 : 2 was decreased when the dietary Delta9cis,12cis-18 : 2 supply was increased.
authors.affiliation: Department of Biochemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China. zhenyuchen@cuhk.edu.hk
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Chen
authors.forename: K Y
authors.initials: KY
authors.lastname: Kwan
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001823:Body Composition / Q000502:physiology*; D001937:Brassica; D019787:Linoleic Acid / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D010084:Oxidation-Reduction; D051381:Rats; D017207:Rats, Sprague-Dawley; D013237:Stereoisomerism
chemical_list: D019787:Linoleic Acid