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Impacts de la musculation sur les signaux chimotactiques

17/09/2014 | Etudes sur les hormones et Etudes Musculation

 

Acute resistance exercise increases the expression of chemotactic factors within skeletal muscle
European Journal of Applied Physiology October 2014, Volume 114, Issue 10, pp 2157-2167   Paul A. Della Gatta

Introduction

Intense resistance exercise causes mechanical loading of skeletal muscle, followed by muscle adaptation. Chemotactic factors likely play an important role in these processes.

Purpose

We investigated the time course of changes in the expression and tissue localization of several key chemotactic factors in skeletal muscle during the early phase of recovery following resistance exercise.

Methods

Muscle biopsy samples were obtained from vastus lateralis of eight untrained men (22 ± 0.5 years) before and 2, 4 and 24 h after three sets of leg press, squat and leg extension at 80 % 1-RM.

Results

Monocyte chemotactic protein-1 (95×), interleukin-8 (2,300×), IL-6 (317×), urokinase-type plasminogen activator (15×), vascular endothelial growth factor (2×) and fractalkine (2.5×) mRNA was significantly elevated 2 h post-exercise. Interleukin-8 (38×) and interleukin-6 (58×) protein was also significantly elevated 2 h post-exercise, while monocyte chemotactic protein-1 protein was significantly elevated at 2 h (22×) and 4 h (21×) post-exercise. Monocyte chemotactic protein-1 and interleukin-8 were expressed by cells residing in the interstitial space between muscle fibers and, in some cases, were co-localized with CD68 + macrophages, PAX7 + satellite cells and blood vessels. However, the patterns of staining were inconclusive and not consistent.

Conclusion

In conclusion, resistance exercise stimulated a marked increase in the mRNA and protein expression of various chemotactic factors in skeletal muscle. Myofibers were not the dominant source of these factors. These findings suggest that chemotactic factors regulate remodeling/adaptation of skeletal muscle during the early phase of recovery following resistance exercise.

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