Skeletal muscle and heart antioxidant defences in response to sprint training

Abstract

Although endurance training enhances the antioxidant defence of different tissues, information on the effect of sprint training is scanty. We examined the effect of sprint training on rat skeletal muscle and heart antioxidant defences. Male Wistar rats, 16-17 weeks old, were sprint trained on a treadmill for 6 weeks. Total glutathione levels and activities of glutathione peroxidase, glutathione reductase, glutathione S-transferase and superoxide dismutase in heart and various skeletal muscles were compared in trained and control sedentary animals. Lactate dehydrogenase and citrate synthase enzyme activities were measured in muscle to test the effects of training on glycolytic and oxidative metabolism. Sprint training significantly increased lactate dehydrogenase activity in predominantly fast glycolytic muscles and enhanced total glutathione contents of the superficial white quadriceps femoris, mixed gastrocnemius and fast-glycolytic extensor digitorum longus muscles. Oxidative metabolic capacity increased in plantaris muscle only. Compared with the control group, glutathione peroxidase activities in gastrocnemius, extensor digitorum longus muscles and heart also increased in sprint trained rats. Glutathione reductase activities increased significantly in the extensor digitorum longus muscle and heart. Glutathione S-transferase activity was also higher in the sprint trained extensor digitorum longus muscle. Sprint training did not influence glutathione levels or glutathione-related enzymes in the soleus muscle. Superoxide dismutase activity remained unchanged in skeletal muscle and heart. Sprint training selectively enhanced tissue antioxidant defences by increasing skeletal muscle glutathione content and upregulating glutathione redox cycle enzyme activities in fast and mixed fibre leg muscles and heart.

Skeletal Muscles Express the Xenobiotic-metabolizing Enzyme ArylamineN-acetyltransferase

“…Variations in muscle cell activity related to aging (Pansarasa et al 1999), chronic immobilization (Kondo et al 1993), or exercise (Atalay et al 1996) modulate the activities of antioxidant enzymes such as cytosolic and mitochondrial superoxide dismutases, catalase, glutathione S -transferase, glutathione reductase, and glucose-6-phosphate dehydrogenase. Ethanol consumption has also been shown to induce CYP1A1/2 in rat skeletal muscle (Smith et al 2000), which supports the potential role of ethanol in the pathogenesis of alcohol-associated rhabdomyolysis in humans (Riggs 1998).…”

Clinical cardioprotection and the value of conditioning responses

“…Several studies have identified improved expression of antioxidants in hearts from exercised animals, including elevations in glutathione (44,133,161), glutathione redox cycle enzyme activities (8), catalase (202), and Mn-SOD (41,202). A number of studies (44,134,176) have also identified beneficial shifts in HSP expression, particularly HSP72.…”

Aspectos atuais sobre estresse oxidativo, exercícios físicos e suplementação

“…Probably, the increase of the oxidative stress imposed to the body during periods of high work volume promotes transitory increase of the activity of antioxidant enzymes (17) . Within this context, Atalay et al (33) have observed in rats submitted to a six-week exercise protocol with supra-maximal intensity an increase in the muscular concentration of total GSH, GPx, glutathione-S transferase (GST) and GR. These results however, were obtained through a treadmill protocol with intensity equivalent to 200% of the VO 2máx of the animals, which makes the extrapolation difficult for humans.…”