Short-term exercise training improves diaphragm antioxidant capacity and endurance

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Andrew Shanely Ph.D, Associate Professor (Creator)
Appalachian State University (ASU )
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Abstract: These experiments tested the hypothesis that short-term endurance exercise training would rapidly improve (within 5 days) the diaphragm oxidative/anti-oxidant capacity and protect the diaphragm against contraction-induced oxidative stress. To test this postulate, male Sprague-Dawley rats (6 weeks old) ran on a motorized treadmill for 5 consecutive days (40± 60 min á day)1) at approximately 65% maximal oxygen uptake. Costal diaphragm strips were excised from both sedentary control (CON, n 14) and trained (TR,n13) animals 24 h after the last exercise session, for measurement of in vitro contraction properties and selected biochemical parameters of oxidative/antioxidant capacity. Training did not alter diaphragm force-frequency characteristics over a full range of submaximal and maximal stimulation frequencies (P > 0.05). In contrast, training improved diaphragm resistance to fatigue as contraction forces were better-maintained by the diaphragms of the TR animals during a submaximal 60-min fatigue protocol (P < 0.05). Following the fatigue protocol, diaphragm strips from the TR animals contained 30% lower concentrations of lipid hydroper-oxides compared to CON (P < 0.05). Biochemical analysis revealed that exercise training increased diaphragm oxidative and antioxidant capacity (citrate synthase activity +18%, catalase activity +24%, total superoxide dismutase activity +20%, glutathione concentration +10%) (P < 0.05). These data indicate that short-term exercise training can rapidly elevate oxidative capacity as well as enzymatic and non-enzymatic antioxidant defenses in the diaphragm. Further-more, this up-regulation in antioxidant defenses would be accompanied by a reduction in contraction-induced lipid peroxidation and an increased fatigue resistance.

Additional Information

Heather K. Vincent, Scott K. Powers, Darby J. Stewart, Haydar A. Demirel, R. Andrew Shanely , Hisashi Naito (2000) "Short-term exercise training improves diaphragm antioxidant capacity and endurance" European Journal of Applied Physiology 81(1-2) Version of Record Available @ (DOI: 10.1007/PL00013799)
Language: English
Date: 2000
diaphragm, oxidative-stress, fatigue, lipid-peroxidation, antioxidants

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