8 Weeks Swimming Discussion Of Myocardial Fibrosis In Diabetic Rats And Its Mechanism

Objective: To observe the effect on myocardial fibrosis indiabetic rats and the possible mechanism of aerobic exercise. Methods:45healthy maleWistar rats of8weeks,a random sample of32only by high-fat diet for7weeks,fasting12h,intraperitoneal injection of30mg/kg STZ buffer,tail vein after72h, Monitoring ofnon fasting blood glucose>16.7mmol/L for modeling success.Normal rats were injectedwith equal volume of citrate buffer solution.The normal rats and the successful modelrats were divided into four groups:The normal control group (group C)、The normalexercise group (group CE)、The diabetic group (DM group)、Diabetic exercise group(group DME).The exercise group improved using Ploug training scheme,withoutload,training6days a week, a total of8weeks of training.Exercise8weekend drawblood fasting blood glucose (FBG),determination of serum insulin retroorbital blood(FINS),and insulin resistance index (HOMA—IR).Part of the left ventricularmyocardium,using the ELISA method for the determination of AngⅡ、TGF-β1、CTGF、COL Ⅰa nd COL Ⅲ; Another partof the left ventricular myocardial tissue were fixedliquid preservation,HE staining and MASSON staining. Results:1. After8weeks ofexercise intervention, DM group and DME group, fasting blood glucose level (FBG)was significantly higher than that of C group and CE group;Blood glucose levels (FBG)in DME group were significantly lower than that of DM group;CE group and C groupshowed no significant difference. Before STZ injection molding, the high fat groupcompared with the nomal group, the serum fasting insulin (FINS) was significantlyelevated;After8weeks of exercise intervention,DM group and DME group, FINS levelwas significantly lower than that of C group and CE group; FINS level of DME wassignificantly higher than that of DM group.2.The body weight of DM group and DMEgroup were significantly lower than those in C group and CE group;DME group andDM group, CE group and C group had no significant difference between the weight.Relative to the DM group and DME group of heart weight (HW/BW) was significantlyhigher than that in C group; there was no significant difference between DME groupand DM group, CE group and C group HW/BW.3.DM group and DME groupmyocardial AngII content was significantly higher than that of C group;DME groupmyocardial AngII content was significantly lower than that of group DM; There was nosignificant difference between group CE and group C, cardiac Ang Ⅱ.DM groupmyocardial content of TGF-β1was significantly higher than that in DME group, C groupand CE group;DME group myocardial content of TGF-β1approaches to the C groupand CE group.Myocardial CTGF content in group DM was significantly higher than that of C group; There was no significant difference between the other groups.4.Myocardium of rats in the DM group myocardial fiber fracture visible change、necrosis、severe hyperplasia,myocardial cells arranged in disorder,edema, degeneration,interstitial congestion;DME group myocardial structural changes have reduced,C groupand CE group myocardial cells showed normal morphology.5Myocardial COLIcontent of DM group was significantly higher than that in DME group, C group and CEgroup; there was no significant difference between DME group, C group and CE group.There was no significant difference among the groups of myocardial COLIII content.Conclusion:1.Type II diabetic model by high-sugar and high-fat diet combined withsmall dose of intraperitoneal injection of STZ replication is successful.2.8weeksaerobic exercise can significantly reduce the blood glucose level in diabeticrats,improvement of insulin resistance,in order to reduce myocardial injury caused bydiabetes mellitus.3.Aerobic exercise has a protective effect on myocardial injury indiabetic rats,can reduce myocardial interstitial fibrosis in diabetic rats,the mechanismmay be related to long-term aerobic exercise decreased myocardial tissue AngII,TGF-β1and CTGF content.