Electron paramagnetic spectroscopic evidence of exercise-induced free radical accumulation in human skeletal muscle.
The present study determined if acute exercise increased free radical formation in human skeletal muscle. Vastus lateralis biopsies were obtained in a randomized balanced order from six males at rest and following single-leg knee extensor exercise performed for 2 min at 50% of maximal work rate (WR(MAX)) and 3 min at 100% WR(MAX). EPR spectroscopy revealed an exercise-induced increase in mitochondrial ubisemiquinone (UQ*-) [0.167 +/- 0.055 vs. rest: 0.106 +/- 0.047 arbitrary units (AU)/g total protein (TP), P < 0.05] and alpha-phenyl-tert-butylnitrone-adducts (112 +/- 41 vs. rest: 29 +/- 9 AU/mg tissue mass, P < 0.05). Intramuscular lipid hydroperoxides also increased (0.320 +/- 0.263 vs. rest: 0.148 +/- 0.071 nmol/mg TP, P < 0.05) despite an uptake of alpha-tocopherol, alpha-carotene and beta-carotene. There were no relationships between mitochondrial volume density and any biomarkers of oxidative stress. These findings provide the first direct evidence for intramuscular free radical accumulation and lipid peroxidation following acute exercise in humans.
Bailey
Damian M
DM
Department of Physiology, Faculty of Life Sciences, University of Glamorgan, Pontypridd, UK. dbailey1@glam.ac.uk
Lawrenson
Leslie
L
McEneny
Jane
J
Young
Ian S
IS
James
Philip E
PE
Jackson
Simon K
SK
Henry
Robert R
RR
Mathieu-Costello
Odile
O
McCord
Joe M
JM
Richardson
Russell S
RS
D000328:Adult; D000975:Antioxidants / Q000032:analysis; D002338:Carotenoids / Q000032:analysis; D003067:Coenzymes / Q000032:analysis; D003497:Cyclic N-Oxides / Q000032:analysis; D004578:Electron Spin Resonance Spectroscopy; D015444:Exercise / Q000502:physiology; D016166:Free Radical Scavengers / Q000032:analysis; D005609:Free Radicals; D006801:Humans; D015227:Lipid Peroxidation; D008054:Lipid Peroxides / Q000032:analysis; D000077276:Lycopene; D008297:Male; D008931:Mitochondria, Muscle / Q000737:chemistry; D009124:Muscle Proteins / Q000032:analysis; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism*; D018384:Oxidative Stress; D013113:Spin Labels; D014451:Ubiquinone / Q000031:analogs & derivatives / Q000032:analysis; D014801:Vitamin A / Q000032:analysis; D024502:alpha-Tocopherol / Q000032:analysis; D019207:beta Carotene / Q000032:analysis
D000975:Antioxidants; D003067:Coenzymes; D003497:Cyclic N-Oxides; D016166:Free Radical Scavengers; D005609:Free Radicals; D008054:Lipid Peroxides; D009124:Muscle Proteins; D013113:Spin Labels; D019207:beta Carotene; D014801:Vitamin A; D014451:Ubiquinone; D002338:Carotenoids; C029217:phenyl-N-tert-butylnitrone; C041635:alpha-carotene; C024989:coenzyme Q10; D024502:alpha-Tocopherol; D000077276:Lycopene