Effects Of Endurance Exercise Of Different Intensities On Skeletal Muscle Autophagy In Aged Rats

The movement of the human body is accomplished through skeletal muscle,the muscle cells that want to create and maintain the tension required by the movement,the organization of the organization must be very careful.Various changes in muscle cells are also very complex,such as the changes in protein,the disappearance of muscle nuclei,and the remodeling of muscle fibers.The loss or alteration of muscle proteins and organelles caused by contraction of muscles is caused by contraction of rmuscles in physical activity.Strengthened with the increase of age,catabolism,the impairment and other damaged cells will be the body through the autophagy pathway,autophagy plays an important role to maintain cellular homeostasis,as stress response in cells subjected to various stimuli is activated,protect the cells.When aging occurs,autophagy can provide energy for new cells to help reduce the occurrence of aging,and its main mechanism is to reduce mTOR activity by activating AMPK factor.It can effectively delay cell senescence and exert the benign effect of autophagy on the body,which can be used to regulate the activity of AMPK.P53,as a tumor suppressor protein,is also an important factor regulating autophagy,which plays an important role in maintaining the balance of cell energy metabolism and delaying the senescence of skeletal muscle.In this study,the effects of p53 on the autophagy signaling pathway AMPK/mTOR in skeletal muscle were detected by different exercise intensity,and the relationship between the autophagy and the autophagy induced by p53 was investigated.Research purposes:this experiment is to old SD rats as the research object,to 8 weeks after different intensity endurance training,testing each group rats soleus p53,AMPK,mTOR,LC3 gene expression,observation of rat skeletal muscle pathological changes,and fluorescence quantitative PCR detection of p53,AMPK,mTOR,amount of LC3 protein expression,to explore in aged rats with different intensity endurance exercise on skeletal muscle cell autophagy.It is speculated that exercise can improve the autophagy induced by p53 and delay cell senescence.Methods:10 male SD rats aged 6 months old were compared with skeletal muscle autophagy in elderly rats.Based at 18 months of age 40 elderly male SD rats,randomly divided into 4 groups(10 in each group),respectively,quiet control group,low intensity,moderate intensity group,higher strength group,exercise load reference to Bedford treadmill training method slightly changes.The quiet control group did not carry out exercise training.In the first week of each exercise group,three adaptive treadmill training sessions were conducted,and the training method was used for 60min/time.The second week began to adjust intensity training,and the low-intensity group adopted 12m/min,60min/d,5d/w,good condition,and the preset training volume could be completed.In the medium strength group,16m/min,60min/d,5d/w,the rat appeared completely unable to meet the predetermined speed,which was still unable to complete after stimulation,but reduced to 15m/min to complete the scheduled training volume;High strength group of 18 m/min,60 min/d,grade 5°,5 d/w,rats appeared completely failed to keep pace with predetermined speed,still unable to complete after stimulation,the prone position,blue,reduce speed is still unable to run after the experiment.Therefore,the reduction intensity was:low intensity group rats:12n/min,60min/d,5d/w,and the maximum oxygen uptake was 50%.Moderate intensity group:15m/min,60min/d,5d/w,the maximum oxygen uptake was 50-60%,the higher intensity group:18m/min,60min/d,5d/w,the maximum oxygen uptake was 6007%-85%.Results:compared with the QC group,the SI value of AC group and LC group was significantly lower(p<0.05),and the difference between MC group and HC group and QC group was not statistically significant(p BBB 0 0.05).Compared with the group AC group,the SI value of LC group was basically unchanged,and the SI value of HC group increased slightly(p>0.05),and the MC group increased significantly(p<0.05).Compared with the group,the SI value of the HC group was slightly higher than that of the LC group(p>0.05),and the MC group was significantly higher than the LC group(p<0.05)and HC group(p<0.05).Note:the effect of different intensity of exercise on the SI value of the rat soleus muscle was different.In the intervention of moderate intensity endurance exercise,the SI value of the soleus muscle was significantly increased.Compared with the group of rats in each group,the number of abnormalities in the myopathology of the rats was observed:the AC group showed the most,compared with the AC group,the group of the LC group,MC group,and HC group showed fewer abnormalities.Expression of p53mRNA:compared with QC group,the gene expression level of MC group and HC group was higher(p<0.05).Compared with the AC group,the gene expression level of MC group and HC group was significantly increased(p<0.05).The gene expression of MC group and HC group was higher than that of LC group(p<0.05).The MC group was higher than the HC group(p<0.05).This indicates that long-term high strength endurance training can improve the expression of p53mRNA,especially in the endurance training with moderate intensity,p<0.01.(4)through autophagy related gene expression quantity:AMPK,Atg7,LC3-b gene expression is consistent,highest QC group(p<0.05),and other groups according to the order from high to low is HC>>AC MC>LC(p<0.05);There was no significant difference between QC and AC group.Compared with the QC group and AC,the differences between LC,MC and HC group were statistically significant and consistent.LC and MC group had more expression volume and less HC group.The expression of LC and MC was significantly higher than that of HC group(p<0.05).The expression of mTORmRNA and other autophagy genes was different in each group:there was no significant difference between QC and AC group(p BBB 0 0.05).Compared with QC group and AC,mTORmRNA expression in LC and MC group was higher(p<0.05).There was no significant difference between LC and MC group(p BBB O 0.05),while LC and MC expression were significantly higher than that in HC group(p<0.05).Conclusion:8 weeks of different intensity endurance training can reduce the pathological abnormality of skeletal muscle in elderly rats,and alleviate the degeneration of skeletal muscle.Moderate and high intensity endurance training can improve the expression of p53 gene in rat soleus muscle and low intensity endurance training.Eight weeks of different intensity endurance training can improve the autophagy level of the rat flatfish muscle and regulate the expression of autophagy gene,which is the best result in the endurance training of medium and high intensity.