Higher Activity of Glutathione Peroxidase in Mature Mice Following a Single Bout of Exercise-Induced Muscle Damage

Oxidative stress is the underlying mechanism of muscle damage following a single bout of exercise. Glutathione peroxidase (GPx) is an endogenous antioxidant that reduces oxidative stress and prevents cell damage in many cases. Following maturation, the GPx protein in the muscle is present at higher levels. The effect of increased GPx protein on oxidative stress and muscle damage is still unknown. Serum skeletal muscle troponin I (sTnI) levels are widely used as a marker for acute muscle damage. In this study, we compared GPx activity and sTnI levels in mature and impremature mice following a single bout of exercise-induced muscle damage. Forty healthy Bbalb/c mice were randomly divided into two groups. Twenty mice were at a mature age of 8 weeks, whereas the other 20 were at an impremature age of 4 weeks. All of the animals performed a single bout of maximum running exercise. Blood serum and calf muscles were collected 24 hours following the end of exercise. GPx activity in the muscle was higher in mature mice compared with that in impremature mice. Serum sTnI levels were lower in mature mice compared with those in impremature mice. Maturation prepares muscles more for defense against oxidative stress and muscle damage.