AMPKβ_2对运动中骨骼肌细胞肌糖原的调节及机理研究

The regulation and mechanism of skeletal muscle glycogen by AMPKβ_2 in training

目的通过饮食和运动的干预,观察大鼠骨骼肌细胞中肌糖原浓度的变化对AMPKβ2蛋白表达和定位的影响,从而进一步推断一次训练课和短期运动、肌糖原浓度变化对AMPKβ2基因表达的影响以及AMPKβ2对肌糖原的调节作用和机理。方法成年雄性wistar大鼠60只,随机分为一次训练组25只,短期运动组35只。高糖组均给予高糖食物和5%蔗糖水饮用,低糖组均给予低糖食物和蒸馏水饮用;除安静组和控制组外,所有大鼠每天适应性游泳30分钟后,分别进行3天和8周的游泳训练。所有大鼠训练宰杀后取大鼠腓肠肌外侧白肌,采用西式印迹分析骨骼肌总蛋白和核蛋白中AMPKβ2的表达水平以及用硫酸蒽酮法测定骨骼肌糖原浓度的变化。结果一次性训练组,骨骼肌细胞总蛋白中AMPKβ2的表达各组比较均没有变化,而在核蛋白中发现,肌糖原浓度显著减低,AMPKβ2的表达升高;短期运动组中,训练前后,低糖组骨骼肌细胞中AMPKβ2在总蛋白中表达升高,而高糖组没有变化,同时高糖组整体肌糖原浓度明显高于低糖组;肌糖原浓度降低的同时,骨骼肌中总蛋白中AMPKβ2表达没有变化,而核蛋白升高;负荷刺激组前后,骨骼肌细胞核蛋白中AMPKβ2表达都明显升高,总蛋白呈现减少趋势,同时肌糖原浓度均降低。结论短期运动中,骨骼肌细胞内肌糖原浓度化与骨骼肌细胞内AMPKβ2蛋白表达有密切关系,低浓度肌糖原促进AMPKβ2蛋白表达,高浓度肌糖原抑制AMPKβ2蛋白表达;无论在高肌糖原还是在低肌糖原以及低肌糖原转高肌糖原模型中,都发现骨骼肌细胞中AMPKβ2定位变化都对应着肌糖原浓度变化,低肌糖原有利于骨骼肌细胞中AMPKβ2的转位,高肌糖原则不利于其转位。

Objective To observe the effect exerted on the protein expression and localization of AMPKβ2 by the variation of strength of muscle glycogen of skeletal muscle cells with the intervening to dieting and sporting of rat in terms of 3 days and 8 weeks respectively,to further deduce the influence on the gene expression and the regulating effect of AMPKβ2 and its mechanism by the variation of strength of muscle glycogen after one-time training and short-term training respectively.Methods 60 adult male Wistar rats were randomly divided into one-time training group and short-term training team.The high-glucose teams fed with high-glucose food and 5% sucrose water.The low-carbohydrates teams fed with low-carbohydrates food and steam water.Besides silent team and controlled team,all rats swam for 30 min.After that,3 days and 8 weeks swimming carried on.The white muscle of the gastrocnemius muscles of all the killed rats was selected.The AMPKβ2 expression level of the total protein and nucleoprotein was detected by the western bolt the variation of strength of muscle glycogen by the anthrone-sulfate method.Results In 3 days training group,the expression of AMPKβ2 of the total protein of Skeletal muscle cell remained the same in all groups.The expression of AMPKβ2 of team low muscle glycogen was higher than that of team high-muscle glycogen,while the strength of muscle glycogen decreased significantly.In the short-term training team,the strength of the muscle glycogen decreased generally,the expression of AMPKβ2 of the total protein of Skeletal muscle cell remained the same,while the nucleoprotein increased.In the sprinting team,the expression of AMPKβ2 of the nucleoprotein of Skeletal muscle cell increased,the total protein showed a decreasing trend,while the strength of muscle glycogen decreased generally.Conclusion In the short term movement,the variation of strength of muscle glycogen closely related to the protein expression of AMPKβ2 in Skeletal muscle cell.The low strength muscle glycogen enhances the protein expression of AMPKβ2,while the high strength muscle glycogen restrains the protein expression of AMPKβ2.The change of localization of AMPKβ2 in Skeletal muscle cell is corresponding to the variation of the strength of muscle glycogen.The low muscle glycogen is favorable to the transposition of AMPKβ2 of Skeletal muscle cell,while high muscle glycogen unfavorable to that.