title: Mitochondrial, sarcoplasmic membrane integrity and protein degradation in heart and skeletal muscle in exercised rats.
abstract: Several different exercise regimens varied in the severity of tissue damage induced. Therefore, this study investigated the effects of a single bout of exercise versus endurance training in heart and skeletal muscles with different predominant fiber types on indices of mitochondrial, endoplasmic reticulum (ER) integrity and protein degradation. Male Wistar rats performed different treadmill exercise protocols: exhaustive, maximal exhaustive, eccentric, training and exhaustive exercise after training. The maximal and eccentric exercises resulted in a significant loss of integrity of the sarcoplasmic and ER muscle, while no changes were observed in cardiac muscle. Mitochondrial membrane fluidity measured by the fluorescence polarization method was significantly increased post-acute exercises in heart and oxidative muscles. Regular exercise can stabilize and preserve the viscoelastic nature of mitochondrial membranes in both tissues. The highest increase in carbonyl content was obtained in heart after exhaustive exercise protocol, from 1+/-0.1 to 3.6+/-0.14 nmol mg protein(-1), such increase were not found after regular exercise with values significantly decreased. Nitrate heart levels showed attenuated generation of nitric oxide after training. Muscle protein oxidation was produced in all exhaustive exercises including eccentric exercise.
authors.affiliation: Department of Physiology, University of Leon, Leon 24071, Spain.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Perez
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Cabral de Oliveira
authors.forename: Emma
authors.initials: E
authors.lastname: Estevez
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Molina
authors.forename: Julio G
authors.initials: JG
authors.lastname: Prieto
authors.forename: Ana I
authors.initials: AI
authors.lastname: Alvarez
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002255:Carbonic Acid / Q000378:metabolism; D005454:Fluorescence Polarization / Q000379:methods; D007425:Intracellular Membranes / Q000201:enzymology / Q000502:physiology*; D008297:Male; D008560:Membrane Fluidity / Q000502:physiology*; D008929:Mitochondria, Heart / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism; D010805:Physical Conditioning, Animal / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*
chemical_list: D009566:Nitrates; D002255:Carbonic Acid; D000469:Alkaline Phosphatase