MAPK信号通路在雄激素和运动对大鼠骨骼肌蛋白合成中的作用

The Role of MAPK Signal Pathway in Synthesizing Skeletal Muscle Protein of Rats Treated with Androgen and Exercise

目的建立大鼠1周耐力运动模型,颈后包埋DHT缓释药片方法进行雄激素刺激,探索MAPK信号通路在雄激素和运动对大鼠骨骼肌蛋白合成中的作用.方法 24只8周龄雄性SD大鼠随机分为4组:安静对照组(NC)、运动对照组(SP)、安静+雄激素组(NCD组)、运动+雄激素组(SPD组);NC组及SP组实施假手术,NCD组和SPD组通过颈后包埋手术方法放置DHT缓释药片;NC组和NCD组安静饲养,SP组和SPD组实施7 d跑台训练.造模结束后,抽提大鼠右侧腓肠肌总蛋白并定量,Western Blot检测各组p38、ERK、JNK总蛋白及磷酸化蛋白表达情况.结果 NC组、SP组、NCD组和SPD组总蛋白含量逐渐增加,且NCD组和SPD组同NC组相比,NCD组增加了16.16%,SPD组增加了19.63%,因此,腓肠肌总蛋白含量差异有统计学意义(P<0.05);SP组、NCD组和SPD组同NC组相比,MAPK信号通路中p38、ERK蛋白磷酸化水平均有升高,且运动和雄激素协同处理组升高最为显著(P<0.05).结论雄激素和运动都增加了骨骼肌总蛋白的合成,且雄激素加强了运动对骨骼肌总蛋白的合成作用;雄激素和运动都有增加骨骼肌p38、ERK、JNK磷酸化趋势,提示雄激素和运动可能通过MAPK信号通路发挥作用.

Objective To establish one week endurance exercise rat model,and put DHT sustained-release tablets in rat neck,explore the role of MAPK signal pathway in rat skeletal muscle protein synthesis induced by androgen and exercise.Methods Twenty-four 8 week old male SD rats were randomly divided into four groups：sedentary control group（NC）,exercise control group（SP）,quiet and androgen group（NCD）,exercise plus androgen group（SPD）;NC group and SP group was given sham operation,NCD group and SPD group was given DHT sustained-release tablets in neck;NC group and NCD group were given no special treatment,SP group and SPD group was given 7 days of treadmill training. After modeling,the total gastrocnemius muscle protein of rats were extracted and quantitatively examined, and the protein expression of ERK,p38,JNK was tested by western Blot.Results The total protein expression levels were increased gradually,and there was a significant difference in the gastrocnemius muscle total protein content（P〈0.05） with in NCD and SPD compared with NC group;in SP group, compared with NC group, the level of phosphorylation ERK, p38, and JNK were increased,and in sports and androgen coordination treatment group was the most significant. Conclusions Androgen and exercise may increase the skeletal muscle protein synthesis, and the androgen could strengthen the effect of exercise on protein synthesis. Androgen and exercise may upregulate the expression of phosphorylated ERK,p38 and JNK in skeletal muscle,and SPD group is the most significant; it suggest that MAPK signal pathway may play a role in androgens and exercise.