| Insulin resistance(Insulin Resistance IR)refers to the insulin signal transduction is weakened or blocked,making the insulin physiological function weakened,resulting in insulin sensitive tissues(liver,skeletal muscle and fat)to reduce glucose uptake and utilization efficiency.It is considered that the unreasonable dietary structure,especially the high fat diet and the sedentary lifestyle are the main causes of IR.Calpain2 is usually slightly expressed in normal physiological conditions,and only in pathological cases.ATG7 is an expression of autophagy related genes involved in lipid metabolism,and a large number of studies have confirmed that the abnormal elevation of Calpain2 may cause the decrease of ATG7 expression and interfere with insulin signal transduction pathway.Exercise as an effective non drug prevention and treatment,research shows that exercise can effectively reduce the expression of Calpain2 and delay the occurrence of IR,but its specific mechanism has not been fully elucidated.Therefore,the purpose of this paper is to study the effect of Calpain2/ATG7 mediated exercise on IR in rats fed with high-fat diet and the mechanism of Calpain2/ATG7 induced by high fat diet induced IR.Research purpose:This study explore the movement of high fat diet intervention effect of insulin resistance in rats and Calpain2 by ATG7 in the role of insulin resistance,exercise intervention analysis the possible mechanism of improving insulin resistance.In order to offer more scientific theoretical foundation for the prevention and treatment of insulin resistance.Research Methods:In 30 SD rats as experimental object,randomly divided into 3 groups: 1?normal diet control group(group C),2?high-fat diet group(group H),IR model 3?high-fat diet group(HE)IR model sports group.Through eight weeks of high-fat feed(calories than 22% protein,45% fat,33% carbohydrates,provide energy of about5305 kcal / 1000 g)feeding rat model of IR was established,and there is no weight loading swimming exercise intervention in rats.Comprehensive utilization of body weight,fasting blood glucose(FBG),fasting insulin(FINS),insulin resistance(HOMA IR)and insulin sensitivity index(ISI)evaluation of the establishment of animal model and the effect of exercise intervention.By observing the movement of the IR rats induced by high-fat diet and ATG7,Calpain2,IRS-1,IRS-1(ser307),AKT,AKT(ser473)protein expression,analysis of the movement of a high-fat diet induced IR rat liver tissue Calpain2/ATG7 classic signaling pathways related factor expression and IR.Explore Calpain2/ATG7 role in the process of insulin resistance and movement in the role.Results:1?8 weeks of high fat fed rats IR animal model: compared with the C group,the H and HOMA-IR of rats in group FINS were significantly higher(p<0.01,p<0.01),ISI was significantly lower(p<0.01).There was no significant difference in FBG of rats(P > 0.05).Compared with H group,the FINS and HOMA-IR of rats in group HE were significantly lower(p<0.05,p<0.01),ISI was significantly increased(p<0.01).There was no significant difference in FBG of rats(P > 0.05).2 ? Changes of body weight in rats: Before the trial there was no significant difference between groups of rats weight(p>0.05).During the experiment,the rats were kept in good condition with bright hair color and normal growth and development.After 8 weeks of experiment,the weight of rats in H group was significantly higher than that of group C(p<0.01),the weight of rats in HE group was significantly lower than that of H group(p<0.01),the weight of rats in HE group and C group had no significant difference(P > 0.05).3?Changes of blood lipid in rats after 8 weeks of regular swimming exercise:Compared with C group,the TG?TC?LDL-C of rats in group H were significantly higher(p<0.05,p<0.05,p<0.01),HDL-C was significantly lower(p<0.05).Compared with H group,the TG ? TC ? LDL-C of rats in group HE were significantly lower(p<0.05,p<0.01,p<0.05)and HDL-C(p<0.05).4 ? The expression of Calpain2 and ATG7 rats 8 weeks of regular swimming:compared with C group,H group expression of rat liver Calpain2 m RNA increased significantly(p<0.01),the expression of ATG7 m RNA was significantly decreased(p<0.01),compared with H rats,the expression of HE in liver tissue rats in group Calpain2 m RNA were significantly lower(p<0.01),the expression of ATG7 m RNA was significantly higher(p<0.01).Compared with C group,H group significantly Increased expression of rat liver tissue Calpain2 protein(p<0.01),significantly reduced the expression of ATG7 protein(p<0.01),compared with H group rats significantly decreased expression of Calpain2 protein in liver tissue of HE rats,(p<0.01),significantly increased the expression of ATG7 protein(p<0.05).5?The expression of IRS-1 and AKT rats 8 weeks of regular swimming:compared with C group,the expression of H in liver tissue of rats in IRS-1m RNA group decreased significantly(p<0.01),compared with H rats,the expression of HE in liver tissue of rats in group IRS-1m RNA were significantly increased(p< 0.01).Compared with C group,the phosphorylation of IRS-1(Ser307)in liver tissue of rats in H group was significantly higher(p<0.01),AKT(ser473)was significantly reduced(p<0.01).Compared with H group,the phosphorylation of IRS-1(Ser307)in liver tissue of rats in HE group was significantly lower(p<0.01),and the phosphorylation of AKT(ser473)was significantly increased(p<0.01).Conclusion:1?8 weeks continuous fat diet can be successfully established animal model of insulin resistance;2?8 weeks regularity swimming can significantly prevent high-fat diet induced insulin resistance in rats;3 ? by 8 weeks,possible mechanisms of swimming exercise to improve IR:motion inhibits the expression of Calpain2,improves the ATG7 espression quantity,makes the IRS-1 increase the activation of PI3K/AKT signal patyway,relieves the IR. |
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