title: Dietary fat effects on hepatic lipid peroxidation and enzymes of H2O2 metabolism and NADPH generation.
abstract: The purpose of this study was to determine the effects of dietary fat quantity and fatty acid composition on hepatic H2O2-metabolizing systems, activities of NADPH-generating enzymes and lipid peroxidation. One-month-old male C57BL/6J mice were fed one of six diets: (i) 5% fat, rich in 18:2n-6 fatty acid (5% N-6); (ii) 20% fat, rich in 18:3n-3 (N-3); (iii) 20% fat, rich in 18:2n-6 (N-6); (iv) 20% fat, rich in 18:1n-9 (N-9); (v) 20% fat, rich in saturated fatty acids (SAT); and (vi) 20% fat, deficient in essential fatty acids (EFAD); for 11 wk. Comparisons between animal groups receiving different fat quantities showed that activities of glucose-6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49) and malic enzyme (ME, EC 1.1.1.40) and the levels of conjugated dienes were significantly lower in the N-6 than in 5% N-6 group. Conversely, activities of catalase (CAT, EC 1.11.1.6) and selenium-glutathione peroxidase (SeGSHPx, EC 1.11.1.9) were higher in the N-6 than in 5% N-6 group. Among the five dietary groups receiving 20% fat but differing in fatty acid composition, CAT activity was lower in the N-9 group, SeGSHPx activity was lower in the EFAD group, and glutathione reductase (GSSGR, EC 1.6.4.2) activity was higher in the N-6 than in the N-3, N-9, SAT and EFAD group. The EFAD group had much higher levels of total lipids and conjugated dienes, as well as activities of NADPH-generating enzymes, including G6PDH, ME and isocitrate dehydrogenase (EC 1.1.1.42), than the other four high-fat groups.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Graduate Center for Toxicology, University of Kentucky, Lexington 40506.
authors.forename: L C
authors.initials: LC
authors.lastname: Chen
authors.forename: G
authors.initials: G
authors.lastname: Boissonneault
authors.forename: M G
authors.initials: MG
authors.lastname: Hayek
authors.forename: C K
authors.initials: CK
authors.lastname: Chow
mesh_terms: D000818:Animals; D004041:Dietary Fats / Q000494:pharmacology*; D005227:Fatty Acids / Q000032:analysis / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009249:NADP / Q000187:drug effects / Q000378:metabolism
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D009249:NADP; D006861:Hydrogen Peroxide