Whole Body Heat Shock Attenuates Impact-Induced Skeletal Muscle Damage In Mice

Impact-induced muscle damage (IIMD) is a common sports injury, often resulting in acute skeletal muscle contractile dysfunction. Whole-body heat shock is reported to attenuate skeletal muscle atrophy in animal models. PURPOSE: The purpose of this study was to test the hypothesis that whole-body heat shock attenuates IIMD related contractile dysfunction and accelerates the recovery of contractile function following IIMD. METHODS: Male mice were randomized to either the whole body heat shock group (WBHS) or the normal body temperature group (NBT). All mice underwent pre-injury in-vivo torque frequency relationship. WBHS mice rectal temperature was raised to 41C for 30min, NBT were maintained at 37C. 24-hours later, all mice were subjected to a single impact-induced injury. Mice were then allowed to recover for 2-hours, 2-days, 5-days, then in-vivo torque frequency relationship was remeasured. RESULTS: 5-days recovery revealed, WBHS fully recovered (p=0.901), and NBT did not recover (p<0.0001) contractile function. 2-days recovery revealed, WBHS recovered (p=0.090), and NBT did not recover (p<0.0001) contractile function. 2-hours recovery revealed both WBHS and NBT did not recover contractile function (p=0.001, p<0.0001 respectively), however at 250hz, WBHS had greater torque compared to NBT (p=0.048).