Epidemiologic investigations have shown that exercise reduces morbidity and mortality from coronary artery disease. In this study, using a rat model, we attempted to determine whether exercise can reduce ischemic injury to the heart and elucidate a mechanism for the cardioprotective effect of exercise. Results showed that exercise significantly reduced the magnitude of a myocardial infarction in biphasic manner. The time course for cardioprotection resembled that of the change in manganese superoxide dismutase (Mn-SOD) activity. The administration of the antisense oligodeoxyribonucleotide to Mn-SOD abolished the expected decrease in infarct size. We showed that the level of tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) increased after exercise. The simultaneous administration of the neutralizing antibodies to the cytokines abolished the exercise-induced cardioprotection and the activation of Mn-SOD. Furthermore, TNF-α can mimic the biphasic pattern of cardioprotection and activation of Mn-SOD. An antioxidant completely abolished cardioprotection and the activation of Mn-SOD by exercise or the injection of TNF-α as well as exercise-induced increase in TNF-α and IL-1β. The production of reactive oxygen species and endogenous TNF-α and IL-1β induced by exercise leads to the activation of Mn-SOD, which plays major roles in the acquisition of biphasic cardioprotection against ischemia/reperfusion injury in rats.
Exercise Provides Direct Biphasic Cardioprotection via Manganese Superoxide Dismutase Activation
N. Yamashita,S. Hoshida,K. Otsu,M. Asahi,T. Kuzuya,M. Hori
Published 1999 in Journal of Experimental Medicine
ABSTRACT
PUBLICATION RECORD
- Publication year
1999
- Venue
Journal of Experimental Medicine
- Publication date
1999-06-07
- Fields of study
Medicine, Chemistry
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
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