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

Abstract

The purpose of this study was to verify the possible appearance in the blood of bradykinin (BK) and des-Arg9-bradykinin (des-Arg9-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-Arg9-BK concentrations were measured by competitive enzyme immunoassays using highly specific polyclonal rabbit IgG. Des-Arg9-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.