Abstract: To explore the protection of aerobic exercise on behavior and endocrine immunity in chronic unpredictable mild stress (CUMS) rats exposed to acute stress. Methods29 healthy male Wistar rats were randomly divided into four groups: the control group, the CUMS model group, the stress with aerobic exercise group, and the stress with labetalol group. Models were produced by a chronic unpredictable mild stress of 21 days. Aerobic exercise and labetalol were used for antistress. After the process of 21 days′ CUMS, acute stress was given. All the rats′ openfield activities were investigated, and serum cortisol and IL1β concentrations were determined by radioimmunoassays. ResultsBehaviors of the CUMS model group had depressive changes. Aerobic exercise not only improved the behavior of CUMS rats but also increased the serum cortisol to a quite normal level, which was higher than that of the CUMS model group and the labetalol group. Labetalol improved the crossings of CUMS rats, while other behavior indexes changed to the contrary. There was no statistical discrepancy of IL1β among groups. ConclusionAerobic exercise could protect CUMS rats against acute stress, which is much better than adrenergic receptor antagonist.

Key words: Stress, Aerobic exercise, Receptor,adrenergic, Behavioral Sciences, Hydrocortisone, Rat,Wistar