| Keywords |
Environment stress ; treadmill exercise ; c-Fos ; HSP 70 ; hippocampus |
| Abstract |
In the present study was to examine the effect of treadmill exercise under heat and cold stress conditions on c-Fos expression in the hippocampus and HSP 70 expression in the gastrocnemius muscle. c-Fos expression represents neuronal activity and plays a crucial role in the brain development. Physical exercise is known to enhance neuronal plasticity and activity. Heat shock protein 70 (HSP 70) is the best characterized stress-responsive gene with enhanced expression and thought to be a protective factor against environmental stress in a cell. For this study, male Sprague-Dawley rats weighing 250±10 g (7 weeks in age) were used. The rats were randomly divided into six groups (n=10 in each group): the control in 4℃ group, the exercise in 4℃ group, the control in 22℃ group, the exercise in 22℃ group, the control in 35℃ group, and the exercise in 35℃ group. The environmental temperature at 22℃ set as the normal conditions, 4℃ was as the cold stress conditions and 35℃ was as the heat stress conditions. In the cold conditions, the temperature was 4℃ with relative humidity 40%. In the normal conditions, the temperature was 22℃ with relative humidity 40%. In the heat stress conditions, temperature was 35℃ with relative humidity 20%. Animals were sacrificed immediately after finishing the last session of treadmill exercise on the 5 weeks of the experiment. The present results showed that exposure under normal, cold and heat stress conditions exerted no signifiant effect on the c-Fos expression. However, the c-Fos expression in the hippocampus was increased by treadmill exercise, showing that cold stress and heat stress acted as the decreasing factor of c-Fos. The HSP 70 expression in the gastrocnemius was increased by treadmill exercise for 5 weeks under normal, cold and heat conditions, however, the increasing of HSP 70 was not appeared that exposure under the cold and heat stress conditions. The present study revealed that treadmill exercise exerted improvement effect on impairment of environmental stress through enhancing of c-Fos and increasing of HSP 70. |