Fluctuations in the skeletal muscle power-velocity relationship and interferon-γ after a muscle-damaging event in humans.
Extrem Physiol Med
; 1(1): 6, 2012 Oct 01.
Article
em En
| MEDLINE
| ID: mdl-23849351
ABSTRACT
BACKGROUND:
Skeletal muscle power is velocity-dependent under constant load conditions. Interferon (IFN)-γ is an inflammatory cytokine that regulates skeletal muscle recovery following insult in experimental animals. It is unknown if the power-velocity relationship and IFN-γ are modulated after a muscle-damaging event in humans. Therefore, the purpose of this study was to identify the power-velocity relationship and circulating IFN-γ concentration responses to a muscle-damaging event in humans.METHODS:
Nine healthy males participated in this study. Each subject had one leg randomly assigned as the control leg. The other leg served as the treatment leg and performed an intense-stretch-shortening cycling (SSC) exercise protocol to induce muscle damage. To measure muscle damage and the power-velocity relationship, unilateral peak isometric force and power output (forces and velocities) measurements were performed prior to, immediately after, and during the days following the SSC protocol. The circulating IFN-γ concentrations were measured in serum samples obtained prior to, immediately after, and during the days following the SSC protocol. Statistical significance of single-leg isometric force and power output data were assessed using a two-way (time and leg treatment) analysis of variance (ANOVA) with repeated measures, followed by a Tukey's honestly significant difference (HSD) to test multiple pairwise comparisons. The statistical significance of the IFN-γ data were assessed using a one-way (time) ANOVA with repeated measures, followed by a Tukey's HSD to test multiple pairwise comparisons.RESULTS:
In the treatment leg, significant (P < 0.05) peak isometric force deficits occurred immediately and persisted several days after the SSC protocol, thereby identifying muscle damage-induced weakness. During muscle weakness in the treatment leg, peak power was significantly (P < 0.05) depressed and the velocities at peak power were significantly (P < 0.05) slower. Interestingly, circulating IFN-γ concentrations decreased at 2 and 3 days after compared to those immediately following the SSC protocol.CONCLUSION:
We conclude that the velocity to achieve a compromised peak power is reduced, and speculatively, the circulating IFN-γ excursion could be influential on the recovery of skeletal muscle after a muscle-damaging event in humans.
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Base de dados:
MEDLINE
Tipo de estudo:
Guideline
Idioma:
En
Revista:
Extrem Physiol Med
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos