Differential effects of a High‐Fructose diet or a High‐Fat/High‐Sucrose diet on the mitochondrial ROS production and respiration in rat liver and skeletal muscle

Abstract

We studied the alterations of the mitochondrial function in response to various hypercaloric diets, and their relation with the occurrence of obesity and/or metabolic syndrome. Male Wistar rats were fed with either standard diet (Control), High‐Fructose (HF) or High‐Fat/High Sucrose (HF/HS) for 6 weeks. Rats under HF/HS displayed increase in body weight, insulin resistance, liver steatosis, and in visceral adiposity when compared to control. In HF/HS, TBARs, AOPP, and antioxidative enzymes were higher in plasma and muscle when compared to control. HF diet but not HF/HS diet was associated to a lower oxygen consumption by liver isolated mitochondria under non phosphorylating conditions whatever the substrate used excepting palmitoyl‐carnitine, compared to control (−30 to −60%). We also report a higher citrate synthase activity in liver tissue in the same condition (+53%) compared to control diet. Activities of complexes II and III are lower in HF and in HF/HS compared to control. H2O2 release by liver isolated mitochondria was higher in HF with succinate as a substrate, compared to the control suggesting alterations of both complex I and III. These results suggest that the type of diet has different effects on mitochondrial function that could related to the obesity and insulin resistance states.This work was supported by the French Agence Nationale pour la Recherche (ANR : project MitHyCal).