电针结合有氧运动对自然衰老大鼠骨骼肌IGF-I/Akt通路的作用

目的:探索低频电针结合有氧运动对增龄性骨骼肌萎缩的效应,以及IGF-I/Akt及其下游蛋白质合成相关通路信号蛋白的影响。方法:以自然衰老SD大鼠为研究对象,将6月龄雄性SD大鼠32只,体重400～450 g,饲养至大鼠12月龄,根据体重随机分为4组。对照组(YC,只抓取、固定、放回,不做其他干预),电针组(YA,电针干预),运动组(YE,运动干预),电针+运动组(YEA,电针结合运动干预),自SD大鼠12月龄开始持续干预至18月龄,实验结束时观察各组自然衰老大鼠:骨骼肌湿重/体重比;光学显微镜下比目鱼肌HE染色形态;Real-time qPCR法检测骨骼肌中IGF-I mRNA的表达水平;Western印迹法测定的大鼠腓肠肌中AKT、mTOR、p70S6K和p-p70S6K相关蛋白表达情况。结果:与YC组相比,YA组、YEA组皆明显增加18月龄大鼠腓肠肌湿重/体重比(P0.05);YEA组能明显增加比目鱼肌湿重/体重比,高于YC组和YA组(P0.05)。与YC组相比,各个干预组大鼠的腓肠肌IGF-I mRNA表达水平皆有上升趋势,其中YEA组IGF-I mRNA表达增加更为明显(P=0.051)。与YC组相比,电针组(YA)p-Akt,p-mTOR表达升高(P0.05),电针+运动组(YEA)p-Akt,p-mTOR,p-p70S6K表达也显示出升高趋势(P0.05)。结论:电针结合有氧运动可延缓18月龄自然衰老大鼠增龄性骨骼肌萎缩,其分子机制可能与通过激活IGF-I/Akt通路,促进蛋白合成有关。

Effect of electroacupuncture combined with aerobic exercise on IGF-I/Akt pathway in skeletal muscle of aging rats

Objective: To explore the effects of low-frequency electroacupuncture combined with aerobic exercise on sarocopenia,and the effects of IGF-I/Akt and its downstream signaling pathway-related protein.Methods: Naturally aging SD rats were used as research objects. Thirty-two 6-month-old male SD rats weighing 400 to 450 g were bred to 12-month-old and randomly divided into 4 groups according to body weight:Control group(YC,only grasp,fix,put back,without other intervention),electroacupuncture group (YA,electroacupuncture intervention),exercise group (YE,exercise intervention) and electroacupuncture+exercise group (YEA,electroacupuncture combined with exercise intervention). SD rats were continuously intervened from 12 months to 18 months of age. At the end of the experiment,the conditions of naturally aging rats in each group were observed:skeletal muscle wet weight/weight ratio;HE staining morphology of soleus muscle under light microscope;qPCR was used to detect the expression level of IGF-I mRNA in skeletal muscle;the expression of AKT,mTOR,p70S6K and p-p70S6K proteins in rat gastrocnemius was determined by Western blot.Results: In 18-month-old rats,the intervention period was 6 months. (1) Compared with YC group,YA group and YEA group significantly increased the wet weight/body weight ratio of gastrocnemius muscle in 18 months old rats. YEA group could significantly increase the wet weight/body weight ratio of soleus muscle compared with YC group YC group and YA group(P<0.05). (2) Compared with YC group,the increase of the expression of IGF-I mRNA in YEA group was more obvious(P=0.051). (3)The expression of p-Akt and p-mTOR in YA group was significantly higher than that in YC group(P<0.05),and the expression of p-mTOR,p-p70S6K also showed an increasing trend in YEA group(P>0.05).Conclusion: Electroacupuncture combined with aerobic exercise can attenuate sarocopenia in 18-month-old naturally aging rats. The molecular mechanism may be related to the promotion of protein synthesis by activating the IGF-I/Akt pathway.