Effects of voluntary exercise on apoptosis and cortisol after chronic restraint stress in mice

PURPOSE To determine whether voluntary exercise (wheel running) has the potential of relieving stress. METHODS In this study, restraint stress with or without voluntary wheel running was performed for mice housed in individual cages. A total of 21 ICR male mice were assigned into control (CON), restraint stress with voluntary exercise (RSVE), or restraint stress (RS) without voluntary exercise groups (n = 7 each). RESULTS No significant difference in body weight increase was found among the three groups, although CON and RS groups had a tendency of having smaller body weight increase compared to the RSVE group. No significant difference in the expression level of liver heat shock protein 70, Bcl-2, or p53 was found among the three groups. However, caspase-3 protein level in RS group was significantly higher than that in the other two groups. Blood cortisol concentration in RS was higher (p < 0.05) than that in RSVE or CON group. It was the lowest (p < 0.05) in the RSVE group. CONCLUSION Our findings suggest that apoptosis caused by chronic restraint stress might be suppressed by voluntary exercise in mice.