High-fat diet induces skeletal muscle oxidative stress in a fiber type-dependent manner in rats

• Published in: Free radical biology & medicine Vol. 110; pp. 381 - 389
• Main Authors: Pinho, Ricardo A., Sepa-Kishi, Diane M., Bikopoulos, George, Wu, Michelle V., Uthayakumar, Abinas, Mohasses, Arta, Hughes, Meghan C., Perry, Christopher G.R., Ceddia, Rolando B.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.09.2017
• Subjects: Animals; Antioxidants; Diet, High-Fat - adverse effects; Fat oxidation; Fiber type; Gene Expression Profiling; Gene Expression Regulation; Male; Mitochondria - metabolism; Mitochondria - pathology; Mitochondrial Uncoupling Proteins - genetics; Mitochondrial Uncoupling Proteins - metabolism; Muscle Contraction - physiology; Muscle Fibers, Skeletal - classification; Muscle Fibers, Skeletal - metabolism; Muscle Fibers, Skeletal - pathology; Myosin Heavy Chains - genetics; Myosin Heavy Chains - metabolism; NADPH Oxidases - genetics; NADPH Oxidases - metabolism; Obesity; Obesity - etiology; Obesity - metabolism; Obesity - pathology; Organ Specificity; Oxidation-Reduction; Oxidative Stress; Peroxiredoxins - genetics; Peroxiredoxins - metabolism; Rats; Rats, Wistar; Reactive oxygen species; Reactive Oxygen Species - metabolism; Skeletal muscle; Antioxidants; Fat oxidation; Obesity; Reactive oxygen species; Skeletal muscle; Fiber type
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2017.07.005

This study investigated the effects of high-fat (HF) diet on parameters of oxidative stress among muscles with distinct fiber type composition and oxidative capacities. To accomplish that, male Wistar rats were fed either a low-fat standard chow (SC) or a HF diet for 8 weeks. Soleus, extensor digitorum longus (EDL), and epitrochlearis muscles were collected and mitochondrial H2O2 (mtH2O2) emission, palmitate oxidation, and gene expression and antioxidant system were measured. Chronic HF feeding enhanced fat oxidation in oxidative and glycolytic muscles. It also caused a significant reduction in mtH2O2 emission in the EDL muscle, although a tendency towards a reduction was also found in the soleus and epitrochlearis muscles. In the epitrochlearis, HF diet increased mRNA expression of the NADPH oxidase complex; however, this muscle also showed an increase in the expression of antioxidant proteins, suggesting a higher capacity to generate and buffer ROS. The soleus muscle, despite being highly oxidative, elicited H2O2 emission rates equivalent to only 20% and 35% of the values obtained for EDL and epitrochlearis muscles, respectively. Furthermore, the Epi muscle with the lowest oxidative capacity was the second highest in H2O2 emission. In conclusion, it appears that intrinsic differences related to the distribution of type I and type II fibers, rather than oxidative capacity, drove the activity of the anti- and pro-oxidant systems and determine ROS production in different skeletal muscles. This also suggests that the impact of potentially deleterious effects of ROS production on skeletal muscle metabolism/function under lipotoxic conditions is fiber type-specific. [Display omitted] •Regardless of fiber type, all muscles compensate for a HF diet by increasing their rates of fatty acid oxidation.•Increases in ROS production and changes to the antioxidant system occur mainly in fast-twitch fibers under HF diet conditions.•Fast-twitch fibers have greater capacity for NAD(P)H-dependent ROS generation.•HF diets stimulate divergent responses in redox buffering and oxidant generating systems across different muscle fiber types.•The results from a single muscle fiber type cannot be used to make generalized conclusions in skeletal muscle as a whole.