Oxidative stress time course in the rat diaphragm after freezing-thawing cycles.
Hyperthermia was shown to induce oxidative stress by uncoupling mitochondrial respiratory chain and to reduce superoxide dismutase (SOD) activity in muscles. Reactive carbonyl groups, malondialdehyde (MDA)-protein adducts, 3-nitrotyrosine immunoreactivity, Mn-SOD, and catalase were detected using immunoblotting in rat diaphragm specimens and homogenates thawed at room temperature (after previous storage at -80 degrees C) for 5, 15, 30, and 60 min, and 3, 6, and 24h to be subsequently and immediately stored at -80 degrees C. Mn-SOD activity was also measured in all muscles. Both total protein carbonylation (reactive carbonyl groups and MDA-protein adducts) and nitration were significantly increased over time, reaching their peaks in the diaphragms of the 60- and 15-min groups, respectively. Mn-SOD expression and activity were significantly reduced over time, while catalase expression showed no significant variation. Protein oxidation was significantly increased in the rat diaphragms exposed to freezing-thawing cycles of different time lengths, while Mn-SOD was substantially reduced in all muscles.
Sellares
Jacobo
J
Muscle and Respiratory System Research Unit, Respiratory Medicine Department, IMIM-Hospital del Mar, Universitat Pompeu Fabra, C/Dr. Aiguader, 80, E-08003 Barcelona, Spain.
Mas
Sandra
S
Melo
Esther
E
Sánchez
Francesc
F
Marin
Judith
J
Gea
Joaquim
J
Barreiro
Esther
E
D000818:Animals; D015153:Blotting, Western / Q000379:methods; D002374:Catalase / Q000378:metabolism; D003964:Diaphragm / Q000502:physiology*; D005615:Freezing; D005786:Gene Expression Regulation / Q000502:physiology; D007035:Hypothermia / Q000378:metabolism / Q000503:physiopathology; D007150:Immunohistochemistry / Q000379:methods; D066298:In Vitro Techniques; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
C002744:3-nitrotyrosine; D014443:Tyrosine; D002374:Catalase; D013482:Superoxide Dismutase