Effects Of Eccentric Weight Training With Different Intensity Loadbearing On Mitofusin 2 And PGC-1? In Rat Gastrocnemius Muscle

Objective: In this experiment,rats with different forms of strength training were taken as research objects.To investigate the effects of concentric weight training and eccentric weight training methods on rat gastrocne protein and gene expression of mitofusin 2(Mfn 2)and peroxisome proliferator-activated receptor ? coactivator 1?(PGC-1?).It provides theoretical basis for the eccentric contraction mechanism,evidence-based medicine for the application of eccentric training to rehabilitation treatment,theoretical basis for formulating clinical exercise programs.Methods: Thirty adult male Sprague-Dawley(SD)rats were randomly divided into a control group,a concentric group,a low-intensity eccentric group,a medium-intensity eccentric group,and high-intensity eccentric group.The concentric group load-bearing reference the mediumintensity eccentric group.Training once a day,30 minutes each time,training for 4 weeks,5 days a week.After exercise training,rats in each group were observed for behavioral performance,body weight,grip,wet weight of gastrocnemius muscle,Western blotting,and real-time quantitative PCR to detect expression of Mfn 2 and PGC-1? protein and m RNA.Results:(1)Behavioral performance of rats: During the entire experiment,compared with the eccentric group,the concentric group had a lower degree of coordination in the late training period.(2)Rat weight: There was no difference in the weight of rats in each group before the experiment(p> 0.05).After the experiment,the weight of the control group was significantly higher than that of the other exercise training groups(p <0.01),high-intensity eccentric group was significantly lower than the rats in each group(p <0.05).(3)Rat grip: After 24 hours of exercise training,the grip performance of each group of rats was: compared with the concentric group,the grip strength of the medium-intensity eccentric group was significantly higher than that of the concentric group(p <0.001),low-intensity eccentric group < medium-intensity eccentric group < high-intensity eccentric group,and there were significant differences in each group(p <0.001).(4)Gastrocnemius wet weight: compared with the concentric group,muscle weight of the medium-intensity eccentric group was significantly higher than the concentric group(p <0.01).Low-intensity eccentric group <medium-intensity eccentric group <highintensity eccentric group,and there were significant differences between the groups(p <0.001).(5)Western blotting and Real-time quantitative PCR: Compared with the concentric group,expression of Mfn2 protein and m RNA of the medium-intensity eccentric group was significantly higher than the concentric group(p <0.01).Expression of Mfn2 protein and m RNA in the eccentric group: low-intensity eccentric group <medium-intensity eccentric group<high-intensity eccentric group,and there were significant differences in each group(p <0.01).Compared with the concentric group,expression of the PGC-1? m RNA in the mediumintensity eccentric group was significantly higher than that in the concentric group(P <0.01).Expression of PGC-1? m RNA in the eccentric group: low-intensity eccentric group <mediumintensity eccentric group <high-intensity eccentric group,and there were statistical differences in each group(p <0.01).Conclusion: The expression of Mfn2,PGC-1? protein and genes in the gastrocnemius muscle of the eccentric training was higher than that in the concentric training;the higher the intensity of eccentric training,the higher the Mfn2,PGC-1? protein and gene expression in the gastrocnemius muscle.