Muscle soreness-induced reduction in force generation is accompanied by increased nitric oxide content and DNA damage in human skeletal muscle.
We examined the effect of exercise-induced muscle soreness on maximal force generation, tissue nitric oxide (NO) and 8-hydroxydeoxyguanosine (8-OHdG) content in human skeletal muscle. Female volunteers were assigned to control (C) and muscle soreness (MS) groups (n = 6 in each). MS group performed 200 eccentric muscle actions of the rectus femoris to induce muscle soreness. Maximal force generation was measured 24 h before and after exercise in both groups. Needle biopsy samples were assayed for NO content with electron spin resonance spectroscopy after ex vivo spin trapping, and 8-OHdG content were measured with an enzyme-linked immuno assay. Maximal force decreased by 11+/-5.4% (p < .05) 24 h after exercise in MS group. Muscle soreness increased NO and 8-OHdG contents from their control values of 0.39+/-0.08 arbitrary units and 0.035+/-0.004 pmol/micromol DNA to 0.96+/-0.05 (p < .05) arbitrary units and 0.044+/-0.005 (p < .05) pmol/micromol DNA, respectively. This is the first demonstration that muscle soreness-induced decrease in maximal force generation is a result of an increase in muscular NO content and associated with enhanced formation of 8-OHdG in human skeletal muscle.
Radák
Z
Z
Laboratory of Exercise Physiology, Hungarian University of Physical Education, Budapest. radak@mte.hupe.hu
Pucsok
J
J
Mecseki
S
S
Csont
T
T
Ferdinandy
P
P
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000032:analysis; D004578:Electron Spin Resonance Spectroscopy; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000502:physiology* / Q000503:physiopathology; D009569:Nitric Oxide / Q000378:metabolism*; D010146:Pain / Q000209:etiology / Q000503:physiopathology*
D009569:Nitric Oxide; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine