Effect Of HIIT On Protein Metabolism Of Skeletal Muscle In SAMP8 Mice

Objective: To explore the changes of protein synthesis and protein decomposition of aging skeletal muscle in HIIT at 16 weeks,to provide a new exercise intervention strategy for early prevention of skeletal muscle quality decline,and to provide a theoretical reference for the application of HIIT in fitness.Methods: Ten SAMR1 mice and 20 SAMP8 mice were divided into normal quiet group SAMR1(NC),fast aging quiet group SAMP8(OC),and fast aging HIIT group SAMP8(OH).Weighing once every four weeks,the quadriceps muscle was completely removed after 16 weeks,weighed wet,HE stained,RT-PCR was used to detect skeletal muscle protein synthesis related factors IGF-1,PI3 K,AKT,m TOR and decomposition related Factor Mu RF-1,MAFbx expression,Western Blot to detect the expression of skeletal muscle protein synthesis-related proteins IGF-1,PI3 K,AKT and decomposition-related proteins Mu RF-1,MAFbx.Results:(1)Compared with the NC group,there was no significant change in body weight in the OC group and the OH group(P> 0.05),but the SI value of the quadriceps muscle was lower than that in the NC group(P <0.05)Compared with the OC group,the SI value of the OH group increased(P <0.05).(2)In terms of morphological examination, compared with the NC group,the number of muscle fibers in the OC group decreased(P <0.01),the number of muscle fibers in the OH group also decreased(P <0.05),and compared with the OC group,the number of muscle fibers in the OH group increased(P <0.05).(3)Compared with the NC group,the expression of IGF-1,PI3 K,AKT,and m TOR m RNA in the OC group were all reduced(P <0.01),while compared with the OC group,the IGF-1(P <0.05),PI3 K in the OH group(P <0.05),AKT(P <0.01),m TOR(P <0.05)m RNA expression increased,but compared with NC group and OH group,OH group IGF-1,PI3 K,AKT,m TOR m RNA expression was still reduced(P <0.05);compared with the NC group,the expression of MURF-1 and MAFbx m RNA in the OC group increased(P <0.01),and the expression of MURF-1 and MAFbx m RNA in the OH group increased(P <0.05);In 0H group,MURF-1 and MAFbx m RNA expression decreased(P <0.05).(4)Compared with the NC group,the expression of IGF-1,PI3 K,and AKT proteins in the OC group were reduced(P <0.01),and compared with the OC group,the expression of IGF-1,PI3 K,and AKT proteins in the OH group were increased.(P <0.01);compared with the NC group,the OC group MURF-1 and MAFbx protein expression increased(P <0.01),compared with the OC group,the OH group MURF-1,MAFbx protein expression decreased(P <0.01).Conclusion:(1)After 16 weeks,SAMP8 mice are already in old age,and 16 weeks of HIIT delays SAMP8 skeletal muscle atrophy.(2)At 16 weeks,HIIT increased protein anabolism,up-regulated the expression of IGF-1 /PI3K/ Akt in mouse quadriceps,and down-regulated the expression of MuRF-1 and MAFbx.