Exercise-induced inflammatory reaction affects electromyographic changes in skeletal muscle during dynamic contractions in humans.
In order to assess the role of exercise-induced inflammatory reactions on electromyographic (EMG) changes in humans, we have recorded, during a 3-min dynamic handgrip exercise at a high strength (112 w), the surface EMG and the compound evoked muscle action potential (M-wave) in control conditions, and this after ingestion of a well known cyclooxygenase blocker i.e. acetylsalicylic acid (ASA), either as a single dose treatment (10 mg/kg) and as a 3-day treatment (30 mg/kg per day). The power spectrum density function of EMG allowed us to compute both the median frequency (MF) and the energies in a low- and a high-frequency band. We estimated the lactic acid concentration from blood samples drawn from an antecubital vein and we noted that its production was not affected by ASA (single dose or 3-day treatment). We observed at the end of exercise that no change in M-wave duration and conduction time occurred though the median frequency always fell. However, we noted that the slope of the MF vs. time regression line was halved after the 3-day ASA treatment which may indicate that inflammatory reactions are elicited by exhausting contractions and affect the EMG changes.
Gainnier
M
M
Laboratoire de Physiopathologie Respiratoire (EA 2201), Institut Jean-Roche, Faculté de Médecine, Université de la Méditerranée, Marseille, France.
Michel
F
F
Fontanari
P
P
Delpierre
S
S
Jammes
Y
Y
D000200:Action Potentials / Q000187:drug effects* / Q000502:physiology; D000328:Adult; D000704:Analysis of Variance; D001241:Aspirin / Q000494:pharmacology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004576:Electromyography / Q000187:drug effects; D015444:Exercise / Q000502:physiology*; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects* / Q000502:physiology; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology
D016861:Cyclooxygenase Inhibitors; D001241:Aspirin