RESUMO
OBJECTIVE: The aim of this study was to investigate the regulatory effects of taurine on the biochemical parameters of muscle injury by overuse. METHODS: Male Swiss mice were divided into four groups: control (Ctrl), overuse (Ov), taurine (Tau), and overuse plus taurine (OvTau). High-intensity exercise sessions were administered for 21 d with concomitant subcutaneous injections of taurine (150 mg/kg). The mice were then sacrificed. The quadriceps muscles were surgically removed for subsequent histologic analysis and evaluation of mitochondrial function, oxidative stress parameters, tissue repair, and DNA damage markers. RESULTS: The Ov group showed significant differences compared with the Ctrl group (all P <0.05). The fiber area decreased by 49.34%, whereas the centralized nuclei contents (Ctrl = 1.33%; Ov = 28.67%), membrane potential (Ctrlsuc = 179.05 arbitrary fluorescence units (AFUs), Ctrlsuc+ADP = 198.11 AFUs; Ovsuc = 482.95 AFUs, Ovsuc+ADP = 461.6 AFUs), complex I activity (Ctrl = 20.45 nmol â min â mg protein, Ov = 45.25 nmol â min â mg protein), hydrogen peroxide (Ctrlsuc = 1.08 relative fluorescence unit (RFU) â sec â mg protein, Ctrlsuc+ADP = 0.23 RFU â sec â mg protein; Ovsuc = 5.02 RFU â sec â mg protein, Ovsuc+ADP = 0.26 RFU â sec â mg protein) and malondialdehyde (Ctrl = 0.03 nmol â mg â protein, Ov = 0.06 nmol â mg â protein) levels, and DNA damage (Ctrlfreq = 7.17%, Ovfreq = 31.17%; Ctrlindex = 4.17, Ovindex = 72.5) were increased. Taurine administration reduced the number of centralized nuclei (OvTau = 5%), hydrogen peroxide levels (OvTausuc = 2.81 RFU â sec â mg protein, OvTaussuc+ADP = 1.54 RFU â sec â mg protein), membrane potential (OvTausuc = 220.18 AFUs, OvTaussuc+ADP = 235.28 AFUs), lipid peroxidation (OvTau = 0.02 nmol/mg protein), and DNA damage (OvTaufreq = 21.33%, OvTauindex = 47.83) and increased the fiber area by 54% (all P <0.05). CONCLUSION: Taken together, these data suggest that taurine supplementation modulates various cellular remodeling parameters after overuse-induced muscle damage, and that these positive effects may be related to its antioxidant capacity.