Increase in blood bradykinin concentration after eccentric weight-training exercise in men

1 Faculté de Pharmacie and 3 Département de Kinésiologie, Université de Montréal, Montreal H3C 3J7; and 2 Département de Kinanthropologie, Université du Québec à Montréal, Montreal, H3C 3P8 Canada The purpose of this study was to verify the possible appearance in the blood of bradykinin (BK) and des-Arg 9 -bradykinin (des-Arg 9 -BK) after eccentric exercise in 13 male subjects. Eccentric exercise (5 × 10 leg presses at 120% maximal voluntary concentric contraction) resulted in muscle damage and inflammation, as suggested by the significant increase in serum creatine kinase activity (from 204 ± 41 to 322 ± 63 U/l 12 h postexercise) and by severe lasting pain, which also peaked at 12 h postexercise. Blood BK and des-Arg 9 -BK concentrations were measured by competitive enzyme immunoassays using highly specific polyclonal rabbit IgG. Des-Arg 9 -BK concentration was not modified (preexercise: 44 ± 14 pmol/l; pooled postexercise: 47 ± 4 pmol/l). In contrast, BK concentration significantly increased immediately after the exercise session (68 ± 9 vs. 42 ± 3 pmol/l preexercise) and returned to basal values at 12, 24, and 48 h (pooled value: 40 ± 4 pmol/l). This observation suggests that the inflammatory process due to eccentric exercise-induced muscle damage could be mediated in part by BK. creatine kinase; delayed-onset muscle soreness; kinins; inflamation; des-Arg 9 -bradykinin