RESUMEN
INTRODUCTION: We evaluated the effect of hyperbaric oxygen treatment (HBOT) in the recovery of muscle injury in rats. MATERIALS AND METHODS: Twelve female Wistar rats, weighing 200-250 g, were submitted to contusion of the right gastrocnemius muscle. Animals were then randomly assigned to an untreated control group or an HBOT-treated group. The HBOT group was given three, 60-minute sessions of HBOT at 253 kPa pressure at 24, 48 and 72 hours post injury. After the last session all animals were sacrificed and both gastrocnemius muscles removed, the left muscle as an internal control. Blood samples were taken for creatine phosphokinase (CPK). Using a standard traction technique, the muscles were analysed for their biomechanical properties: hardness, maximum elongation and maximum weight. RESULTS: Significant differences were found between uninjured and injured muscles and between untreated and HBOT groups in maximum weight and hardness: maximum weight in the non-treated group 18.27 ± 2.99 N versus 26.18 ± 2.84 N in the HBOT group (P = 0.007); hardness in the non-treated group 2.24 ± 0.38 103 N m⻹ versus 3.19 ± 0.32 10³ N m⻹ in the HBOT group (P = 0.001). The difference in maximum elongation was not significant (P = 0.793). CPK was significantly different between the two groups (non-treated 6,445 ± 387 i.u. L⻹; HBOT 4,551 ± 80 i.u. L⻹; P = 0.009). CONCLUSIONS: HBOT seems to play a positive role in the recovery of induced muscle injury in rats. However relevant, these results cannot be extrapolated to humans, for whom further clinical studies are warranted.
