Strenuous Acute Exercise Induces Slow and Fast Twitch-Dependent NADPH Oxidase Expression in Rat Skeletal Muscle

• Published in: Antioxidants Vol. 9; no. 1; p. 57
• Main Authors: Osório Alves, Juliana, Matta Pereira, Leonardo, Cabral Coutinho do Rêgo Monteiro, Igor, Pontes Dos Santos, Luiz Henrique, Soares Marreiros Ferraz, Alex, Carneiro Loureiro, Adriano Cesar, Calado Lima, Crystianne, Leal-Cardoso, José Henrique, Pires Carvalho, Denise, Soares Fortunato, Rodrigo, Marilande Ceccatto, Vânia
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 08.01.2020; MDPI
• Subjects: Adaptation; Animals; antioxidant defenses; Antioxidants; Catalase; CYBB protein; Detoxification; Enzymatic activity; Enzymes; Exercise; Fitness equipment; Gene expression; Glutathione peroxidase; Glycogen; Glycolysis; glycolytic metabolism fibers; Isoforms; Mitochondria; Musculoskeletal system; NAD(P)H oxidase; NADPH-diaphorase; NOX4 protein; Oxidation; oxidative metabolism fibers; Oxidative stress; Production increases; Proteins; Reactive oxygen species; Skeletal muscle; skeletal muscle fibers; Sodium; Soleus muscle; Superoxide dismutase; Brazil; United States > US; oxidative metabolism fibers; antioxidant defenses; glycolytic metabolism fibers; reactive oxygen species; skeletal muscle fibers
• ISSN: 2076-3921; 2076-3921
• DOI: 10.3390/antiox9010057

The enzymatic complex Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase (NOx) may be the principal source of reactive oxygen species (ROS). The NOX2 and NOX4 isoforms are tissue-dependent and are differentially expressed in slow-twitch fibers (type I fibers) and fast-twitch fibers (type II fibers) of skeletal muscle, making them different markers of ROS metabolism induced by physical exercise. The aim of this study was to investigate NOx signaling, as a non-adaptive and non-cumulative response, in the predominant fiber types of rat skeletal muscles 24 h after one strenuous treadmill exercise session. The levels of mRNA, reduced glycogen, thiol content, NOx, superoxide dismutase, catalase, glutathione peroxidase activity, and and gene expression were measured in the white gastrocnemius (WG) portion, the red gastrocnemius (RG) portion, and the soleus muscle (SOL). NOx activity showed higher values in the SOL muscle compared to the RG and WG portions. The same was true of the NOX2 and NOX4 mRNA levels, antioxidant enzymatic activities, glycogen content. Twenty-four hours after the strenuous exercise session, NOx expression increased in slow-twitch oxidative fibers. The acute strenuous exercise condition showed an attenuation of oxidative stress and an upregulation of antioxidant activity through gene activity, antioxidant defense adaptations, and differential gene expression according to the predominant fiber type. The most prominent location of detoxification (indicated by NOX4 activation) in the slow-twitch oxidative SOL muscle was the mitochondria, while the fast-twitch oxidative RG portion showed a more cytosolic location. Glycolytic metabolism in the WG portion suggested possible NOX2/NOX4 non-regulation, indicating other possible ROS regulation pathways.