降钙素基因相关肽对大鼠运动性疲劳的影响

摘要

The purpose of this paper is to study the effects of CGRP on the exercise-induced fa-tigue 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 pretreat-ment group ,the CGRP pretreatment group ,the CAP pretreatment group ,the CAP pretreat-ment + CGRP pretreatment group .The rats were sacrificed at the resting state ,the exercise to 80 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 de-tecting the change of superoxide dismutase ,glutathione peroxidase ,catalase ,and malondialde-hyde at the conditions of the different pretreatment .Results :1) The time of the treadmill exer-cise 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 immunoposi-tive 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 expres-sion of CGRP was significantly decreased after the CAP pretreatment (P< 0 .05) .3) HE stai-ning showed that there were no obvious differences in amorphous constitution of skeletal mus-cle in all groups at the resting state .There were also no obvious changes in morphous constitu-tion 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 aug-mented 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 in-creased (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-in-duced fatigue .%目的：探讨降钙素基因相关肽（CGRP ）对大鼠运动性疲劳的影响。方法：成年健康雄性SD大鼠，依据不同的预处理措施随机分成5组：空白对照组、磷酸盐缓冲液（PBS ）预处理组、CGRP预处理组、辣椒素（CAP ）预处理组、CAP预处理＋ CGRP预处理组，各组动物在安静状态时、运动80 min时和运动至力竭后即刻处死。然后用免疫组化和放射免疫方法检测上述条件下大鼠腓肠肌神经肌肉接头CGRP的表达变化；用苏木精-伊红（HE）染色观察上述条件下运动性疲劳大鼠骨骼肌形态结构的变化；用化学比色的方法检测上述条件下骨骼肌超氧化物歧化酶（SOD ）、谷胱甘肽过氧化物酶（GSH-PX ）、过氧化氢酶（CAT ）及丙二醛（MDA ）的变化。结果：1）给予 CGRP 预处理后，大鼠运动至力竭的时间明显缩短（ P＜0．05），而给予CAP预处理后大鼠运动至力竭的时间明显延长（ P＜0．05）；2）CGRP免疫组织化学和放射免疫结果显示，CGRP的免疫阳性产物在肌纤维纵切面上，其形状为椭圆形或棒状，主要分布于肌纤维膜的表面。给予CGRP预处理后，大鼠腓肠肌神经肌肉接头CGRP的表达明显升高（ P＜0．05），而给予CAP预处理后，大鼠腓肠肌神经肌肉接头CGRP的表达明显下降（ P＜0．05）；3）HE染色显示，安静状态下各组骨骼肌的形态结构未见明显改变；与安静状态相比，运动80min时除CGRP预处理组骨骼肌的细胞核明显增多、增大外，其余各组均无明显改变；力竭运动后即刻与安静状态下相比，除CAP预处理组无明显改变外，其余各组骨骼肌的细胞核均明显增多、增大；4）化学比色结果显示，给予CGRP预处理后，大鼠骨骼肌中SOD、GSH-PX 和CAT 的活性明显下降（ P＜0．05），MDA的含量明显上升（ P＜0．05），而给予CAP预处理后大鼠骨骼肌中 SOD、GSH-PX 和 CAT 的活性明显上升（ P＜0．05）， MDA的含量明显下降（ P＜0．05）。结论：CGRP 加剧了运动性疲劳的产生。