Effects Of Aerobic Exercise On Skeletal Muscle NO,SIRT1 In The Process Of Prevention Type 2 Diabetes In Mice

Content:At present,the number of patients with type 2 diabetes mellitus(T2DM)in China and the world is increasing which has aroused the concern of all scholars.It is very important to find a way to prevent T2 DM because it is difficult to cure.Regular exercise is an effective means to promote metabolic adaptation and control of multiple metabolic diseases.Nitric oxide(NO)is an inorganic molecule that acts as a signaling molecule among cells and is extensively studied in the fields of physiology,biochemistry and biomedicine.Silent mating type information regulation factor 2 homologous protein 1(SIRT1)is involved in the physiological processes of glucose/lipid metabolism,mitochondrial biosynthesis and so on.Recent studies have shown that exercise can improve the insulin sensitivity of skeletal muscle in patients with T2 DM by NO/SIRT1-mediated regulatory pathway.But the role of this pathway is rarely reported during the prevention of T2 DM.In this study,we observed the activity of nitric oxide synthase(NOS),the content of NO and the expression of SIRT1 protein in mouse gastrocnemius muscle of high glucose and high fat diet mice after aerobic exercise intervention.To determine the aerobic exercise has an important role in regulating fasting blood glucose,regulating insulin sensitivity and preventing T2 DM when it stimulates mouse gastrocnemius muscle NOS/NO and SIRT1,to provide new ideas for the prevention of T2 DM.Method:24 8-week-old male Balb/Cj strain mice were randomly divided into four groups: normal group(CC group),aerobic exercise group(EC group),high glucose and high fat diet group(HC group),aerobic exercise + high glucose and high fat diet group(HE group),6 per group.The mice in the EC and HE groups were followed by a 6-week treadmill test,increasing from 10 m/min to 15 m/min,increasing the rate once a week(1 m/min),5 times a week,with a duration of 45 min,the slope is 0.CC group and EC group were fed with normal diet.HC group and HE group were fed with high glucose and high fat diet.The fasting blood glucose(FBG)level was measured by Roche blood glucose meter before sacrifice,and the fasting insulin(FIN)content was measured by ELISA.Then calculate the insulin sensitivity index(ISI)and insulin resistance index(IR).The activity of NOS,the content of NO in the gastrocnemius muscle of mice were detected by biochemical kit and the expression of SIRT1 protein in the gastrocnemius muscle of mice was detected by Western blot.The data were analyzed by SPSS20.0 software in two-way ANOVA.Results:(1)After 6 weeks of intervention,the levels of FBG and FIN in HC group were higher than those in CC group.HE group and EC group were lower than HC group.Effects of aerobic exercise and high glucose and high fat diet on the level of FBG in mice was significant(P <0.01),on the level of FIN in mice was significant(P <0.01,P <0.05).HC group of mice ISI was lower than the CC group and HE group.EC group were higher than HC group and CC group.Effects of aerobic exercise and high glucose and high fat diet on ISI in mice were significant(P <0.01)HC group of mice ISI was higher than CC group.HE group and EC group were lower than HC group and CC group.Effects of aerobic exercise and high glucose and high fat diet on IR in mice were significant(P <0.01).(2)Interaction effects of aerobic exercise and high glucose and high fat diet on the activity of tNOS and iNOS in mouse gastrocnemius muscle were significantly(P <0.01).The activity of tNOS and iNOS in the gastrocnemius muscle of the HE group were lower than those in the HC group(P <0.01).The activity of tNOS in EC group was higher than that in CC group.The activity of iNOS in EC group was not different from that in CC group.Effects of aerobic exercise and high glucose and high fat diet on cNOS activity in mouse gastrocnemius were significantly(P <0.01).The activity of cNOS in gastrocnemius muscle of HE group was higher than that of HC group,EC group was higher than CC group.(3)Interaction effects of aerobic exercise and high glucose and high fat diet on the content of NO in mouse gastrocnemius was significantly(P <0.05).After 6 weeks,HE group was lower than HC group.The effect of aerobic exercise on NO content in gastrocnemius muscle of high glucose and high fat diet mice was significant(P <0.05),and had no effect on common dietary mice.(4)Interaction effects of aerobic exercise and high glucose and high fat diet on the expression of SIRT1 protein in mouse gastrocnemius muscle were significantly(P <0.05).The expression of SIRT1 protein in gastrocnemius muscle of HE group was higher than that of HC group.The effect of aerobic exercise on the expression of SIRT1 protein in gastrocnemius muscle of high glucose and high fat diet mice was significant(P <0.01),and had no effect on common dietary mice.Conclusion:(1)Aerobic exercise reduced the fasting blood glucose level and fasting insulin content of high glucose and high fat dietary mice,and increased the insulin sensitivity of high glucose and high fat dietary mice and reduced the insulin resistance.(2)Aerobic exercise reduced the activity of tNOS in the gastrocnemius muscle of high glucose and high fat diet mice.Help to alleviate the high glucose and high fat diet mice a significant increase in the content of NO.(3)Aerobic exercise significantly increased the expression of SIRT1 protein in the gastrocnemius muscle of high glucose and high fat diet mice.