Effects Of Blood Flow Restriction Combined With Resistance Training On Insulin Resistance In Skeletal Muscle Of T2DM Rats

Objective: to observe the regulatory effects of different exercise modes on glucose metabolism and the changes of PI3K/AKT signal pathway and GLUT4 related to glucose metabolism in T2 DM rats through 8-week exercise intervention,so as to provide theoretical basis for the clinical application of blood flow restriction training as an auxiliary means to improve type 2 diabetes mellitus.Methods: 80 8-week-old male SD rats were randomly divided into normal control group(NC,n=10)and model group(nude 70).The normal control group was fed with normal diet,and the model group was fed with highfat diet followed by intraperitoneal injection of 35mg/kg STZ for eight weeks to establish type II diabetes model.The successful rats were randomly divided into diabetic quiet control group(DM,n=11),low intensity resistance training group(DL,n=11),high intensity resistance training group(DH,n=12),simple blood flow restriction group(DR,n=12)and blood flow restriction with resistance training group(DLR,n=12).Exercise intervention was conducted for eight weeks.DL group received35%-55%1RM gradual low-intensity resistance ladder training,DH group received 55%-75%1RM gradual high-intensity resistance ladder training,DR group received simple 30% Mel 40% blood flow restriction training,DLR group received 35%-55%1RM gradual low-intensity resistance ladder training combined with 30% Mel 40% blood flow restriction training.Random blood glucose and body weight were measured every Monday.After 8 weeks of exercise intervention,arterial blood samples and quadriceps femoris were taken to detect insulin and IGF-1;immunofluorescence to observe GLUT4 transport,and Western Blot to detect the relative protein expressions of PI3 K,p-PI3 K,AKT,p-AKT and GLUT4 in quadriceps femoris.Results:(1)after 8 weeks of exercise intervention,the random blood glucose of rats in T2 DM exercise group decreased,and the random blood glucose of DL,DR and DLR were significantly different from those before intervention(DL,DR:P < 0.01),but there was no significant difference between NC group and DLR group(P > 0.05).(2)after 8 weeks of exercise intervention,there were significant differences in fasting blood glucose,HOMA-IR and HOMA-β between NC group and each T2 DM group.Different exercise intervention methods improved fasting blood glucose,HOMA-IR and HOMA-β to some extent,of which DLR improved the most,but there was no significant difference.(3)after 8 weeks exercise intervention,except for DR group,different exercise intervention methods improved p-PI3K/PI3 K and p-AKT/AKT of skeletal muscle,and there was significant difference in p-AKT/AKT expression between DLR group and DM group(P > 0.05).(4)after 8-week exercise intervention,compared with DM group,the expression of GLUT4 in muscle cells in DL and DH groups increased significantly,and that in DLR group increased significantly(P < 0.05).(5)after 8-week exercise intervention,compared with DM group,the expression of GLUT4 in muscle cell membrane increased significantly in all exercise groups,and significantly increased in DL,DH and DLR groups.Conclusion:(1)in this study,many kinds of exercise can improve diabetes,among which blood flow restriction combined with resistance training has the best effect,which can reduce random blood glucose in type 2 diabetic rats.it also plays a certain role in improving glucose metabolism related indexes,but the effect is not significant.There were significant differences in serum IGF-1,AKT phosphorylation level,GLUT4 relative expression and cell membrane GLUT4 relative expression between the two groups,which provided a theoretical basis for blood flow limitation with resistance training in the prevention and treatment of insulin resistance in type 2diabetes mellitus.(2)the effect of low-intensity resistance training on improving glucose metabolism is not significant,but there is a significant difference in increasing the content of p-AKT,GLUT4 and translocation,which can be used as one of the ways to improve diabetes.(3)the improvement effect of high intensity resistance training on the percentage of quadriceps femoris to body weight is the best,and the improvement effect of glucose metabolism related index and protein level is not as good as that of low intensity resistance training and blood flow restriction with resistance training.(4)the effect of simple blood flow restriction training on improving the related indexes of glucose metabolism is far less than that of other exercise interventions,and has a negative effect on the relative expression of IGF-1,p-PI3 K and GLUT4.