Effects of Calcitonin Gene-related Peptide on the Exercise-induced Fatigue of Rats

The purpose of this paper is to study the effects of CGRP on the exercise-induced fatigue of rats.Methods:Healthy adult male Sprague– Dawley rats were randomly divided into five groups according to the different pretreatment:the blank control group,the PBS pretreatment group,the CGRP pretreatment group,the CAP pretreatment group,the CAP pretreatment +CGRP pretreatment group.The rats were sacrificed at the resting state,the exercise to80 min and the exercise to exhaustion,Then the immunohistochemistry and radioimmunoassay was used to detecting the expression of CGRP at the condition of the different pretreatment,the HE staining was used to detecting the change of morphous formation of skeletal muscle at the condition of the different pretreatment,the chemistry colorimetric method was used to detecting the change of superoxide dismutase,glutathione peroxidase,catalase,and malondialdehyde at the conditions of the different pretreatment.Results:1)The time of the treadmill exercise to exhaustion was significantly decurtated after CGRP pretreatment(P<0.05),and the time of the treadmill exercise to exhaustion was significantly prolonged after CAP pretreatment(P<0.05).2)Immunohistochemistry and radioimmunoassay showed that CGRP immunopositive products were elliptical or rod-shape at longitudinal section of muscle fiber.The expression of CGRP was significantly increased after the CGRP pretreatment(P<0.05),and the expression of CGRP was significantly decreased after the CAP pretreatment(P<0.05).3)HE staining showed that there were no obvious differences in amorphous constitution of skeletal muscle in all groups at the resting state.There were also no obvious changes in morphous constitution of skeletal muscle at the other groups at the exercise to 80 min than at the resting state,excluding cell nucleus of skeletal muscle were significantly increased and augmented at the CGRP pretreatment group,Cell nucleus of skeletal muscle were significantly increased and augmented in all other groups,while there were no obvious changes in morphous constitution of skeletal muscle at the CAP pretreatment group at exercise to exhaustion than at the resting state.4)The chemistry colorimetric showed that the content of MDA was significantly increased(P<0.05),and the activity of SOD,GSH-PX,CAT was significantly decreased after the CGRP pretreatment(P<0.05),While the content of MDA was significantly decreased(P<0.05),and the activity of SOD,GSH-PX,CAT was significantly increased after the CAP pretreatment(P<0.05).Conclusions:The CGRP intensified the generation of exercise-induced fatigue.