雷帕霉素和LY294002对游泳训练大鼠骨骼肌生长及PI3K/Akt/mTOR信号通路的影响

Effects of Rapamycin and LY294002 on the PI3K/Akt/mTOR Pathway in Rat Skeletal Muscle with Swimming Training

目的:探讨LY294002和Rapamycin对运动性骨骼肌PI3 K/Akt/mTOR上游信号通路抑制效应,为骨骼肌生长的分子机制提供实验依据。方法:以40只成年SD大鼠为对象,采用负重15%间歇游泳训练方式建立运动模型。动物分组为安静对照组(C),运动组(T),运动+LY294002组(TL),运动+Rapamycin组(TR),运动+LY294002+Rapamycin组(TRL)。取左、右侧腓肠肌和比目鱼肌,采用westren blotting技术检测骨骼肌Akt、PI3 K、mTOR及其磷酸化水平。结果:8周训练后,各实验组骨骼肌质量无显著性差异(P>0.05),但T组腓肠肌和比目鱼肌肉质量指数均显著高于对照组。与对照组相比,T组大鼠骨骼肌P-PI3 K/PI3 K、P-Akt/Akt、P-mTOR/mTOR比值略增加(P>0.05),但TR、TLR组均有显著下降(P<0.05)。结论:间歇性游泳负荷训练能够促进骨骼肌生长,且与PI3 K/Akt/mTOR信号通路有关。LY294002和Rapamycin对运动引起的PI3 K/Akt/mTOR信号通路有抑制作用。

Objective. To examine the association between the PI3K/Akt/mTOR pathway and the skeletal muscle growth and its potential mechanism responding to swimming training. Methods： 40 male SD rats were divided into control group （C） and training group （T）, and used to establish swimming training models with a 15 % weight load. The training adopted interval training protocol with load and training every other day with 8 weeks. The gastrocnemius and soleus muscle were collected and weighed after training, and the protein expression of PI3K,Akt, roTOR and their activated forms were examined. Results.. After 8 weeks treatment, no significant was observed in skeletal muscle mass between groups, but the Soleus and Gastrocnemius Muscle Mass Index in training T group increased significantly compared with control group（P〈0. 05）. Compared with the control group, the ratio of P-PI3K/PI3K, P- Akt/Akt,P-mTOR/mTOR in T group increased with insignificant difference, but the ratio in TR and TRL groups was significantly reduced （P〈0. 05）. Conclusions： these results suggest that the interval training protocol is helpful to increase the relative muscle hypertrophy, LY294002 and Rapamycin has an inhibition role in the PI3K/Akt/mTOR pathway responding to training.