title: Hepatic mitochondrial energetics during catch-up fat with high-fat diets rich in lard or safflower oil.
abstract: We have investigated whether altered hepatic mitochondrial energetics could explain the differential effects of high-fat diets with low or high ω6 polyunsaturated fatty acid content (lard vs. safflower oil) on the efficiency of body fat recovery (catch-up fat) during refeeding after caloric restriction. After 2 weeks of caloric restriction, rats were isocalorically refed with a low-fat diet (LF) or high-fat diets made from either lard or safflower oil for 1 week, and energy balance and body composition changes were assessed. Hepatic mitochondrial energetics were determined from measurements of liver mitochondrial mass, respiratory capacities, and proton leak. Compared to rats refed the LF, the groups refed high-fat diets showed lower energy expenditure and increased efficiency of fat gain; these differences were less marked with high-safflower oil than with high-lard diet. The increase in efficiency of catch-up fat by the high-fat diets could not be attributed to differences in liver mitochondrial activity. By contrast, the lower fat gain with high-safflower oil than with high-lard diet is accompanied by higher mitochondrial proton leak and increased proportion of arachidonic acid in mitochondrial membranes. In conclusion, the higher efficiency for catch-up fat on high-lard diet than on LF cannot be explained by altered hepatic mitochondrial energetics. By contrast, the ability of the high-safflower oil diet to produce a less pronounced increase in the efficiency of catch-up fat may partly reside in increased incorporation of arachidonic acid in hepatic mitochondrial membranes, leading to enhanced proton leak and mitochondrial uncoupling.
authors: Department of Structural and Functional Biology, University of Naples, Naples, Italy.
authors: Raffaella
authors: R
authors: Crescenzo
authors: Francesca
authors: F
authors: Bianco
authors: Italia
authors: I
authors: Falcone
authors: Sofia
authors: S
authors: Tsalouhidou
authors: Gayathri
authors: G
authors: Yepuri
authors: Vassilis
authors: V
authors: Mougios
authors: Abdul G
authors: AG
authors: Dulloo
authors: Giovanna
authors: G
authors: Liverini
authors: Susanna
authors: S
authors: Iossa
mesh_terms: D000154:Aconitate Hydratase / Q000378:metabolism; D000818:Animals; D001823:Body Composition; D031204:Caloric Restriction; D059305:Diet, High-Fat; D004041:Dietary Fats / Q000494:pharmacology*; D004734:Energy Metabolism; D015227:Lipid Peroxidation; D008099:Liver / Q000378:metabolism*; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism*; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D012450:Safflower Oil / Q000494:pharmacology*; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism*; D000072105:Superoxide Dismutase-1
chemical_list: D004041:Dietary Fats; D012450:Safflower Oil; D013230:Stearoyl-CoA Desaturase; C000606292:Sod1 protein, rat; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D000154:Aconitate Hydratase; C029310:lard