Plasma matrix metalloproteinase-9 response to eccentric exercise of the elbow flexors

• Published in: European journal of applied physiology 2011-08, Vol.111 (8), p.1795-1805
• Main Authors: Madden, Molly C., Byrnes, William C., Lebin, Jacob A., Batliner, Matthew E., Allen, David L.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Biological and medical sciences; Biomarkers - blood; Biomarkers - metabolism; Biomedical and Life Sciences; Biomedicine; Elbow; Elbow - physiology; Elbow Joint - metabolism; Elbow Joint - physiology; Exercise; Exercise - physiology; Fundamental and applied biological sciences. Psychology; Human Physiology; Humans; Isometric Contraction - physiology; Kinases; Male; Males; Matrix Metalloproteinase 9 - blood; Matrix Metalloproteinase 9 - metabolism; Matrix Metalloproteinase 9 - physiology; Muscle Contraction - physiology; Muscle Fatigue - physiology; Muscular Diseases - blood; Muscular Diseases - diagnosis; Muscular Diseases - enzymology; Muscular Diseases - metabolism; Musculoskeletal system; Occupational Medicine/Industrial Medicine; Original Article; Physical fitness; Plasma; Range of Motion, Articular - physiology; Sports Medicine; Torque; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports; Young Adult; Young adults
• ISSN: 1439-6319; 1439-6327
• DOI: 10.1007/s00421-010-1806-y

Recent efforts to establish a role for plasma matrix metalloproteinase-9 (MMP-9) as a marker of exercise-induced muscle damage have been inconsistent. Methodological and experimental design issues have contributed to confusion in this area. The purpose of this study was to use a damaging eccentric arm task to evaluate the relationship between activity-induced muscle damage and plasma MMP-9 levels in humans while controlling for physical activity history and quantifying day-to-day variability of the dependent variables. Fourteen physically inactive males performed 6 sets of 10 eccentric contractions of the elbow flexors at 120% of their voluntary concentric maximum. Soreness ratings, maximum voluntary isometric strength, range of motion (ROM), limb circumference, and plasma creatine kinase (CK) and MMP-9 levels were measured at 2 time points before, immediately after, and 1, 2, 4, and 7 days post-exercise. Changes in traditional markers of muscle damage mirrored patterns previously reported in the literature, but plasma MMP-9 concentration and activity measured by ELISA and gelatin zymography were unchanged at all time points examined. Plasma levels of the MMP-9 inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), were also unchanged post-exercise. Finally, although mean MMP-9 levels were not significantly different between the two pre-exercise timepoints, the high total error of measurement and low day-to-day correlation suggest substantial within and between subject variability. Plasma MMP-9 levels are not a robust or reliable marker for eccentric exercise-induced damage of the elbow flexor musculature, though this may not preclude a role for MMPs in skeletal muscle remodeling in response to injury.