| Significance: The significance of this topic lies in the experimental study of animal models of diabetes.Different interventions were adopted to provide theoretical basis for the prevention and treatment of clinical type 2 diabetes(T2DM)complicated with cardiomyopathy.Through the combination of medical prescriptions and exercise prescriptions,it provides more safe and effective preventive measures for patients with type 2 diabetes complicated by cardiomyopathy.Objectives: This study was to investigate the effects of anti-impeded exercise combined with metformin(MET)intervention on myocardial fibrosis in type 2 diabetic rats.The study was based on the histomorphology,physiological and biochemical indicators,and the expression of TGF-β1,MMP-9 and TIMP-1protein in myocardial tissue.The effect of resistance exercise combined with metformin intervention on myocardial fibrosis in type 2 diabetic rats is provided,which provides a theoretical basis for clinical prevention and treatment of diabetic cardiomyopathy(DCM).Methods:Fifty male SD rats were randomized to receive 10 nuclei as the normal control group(NC group),the other 40 were fed with high-sugar and high-fat diet for 4 weeks and intraperitoneal injection of 1% STZ to establish type 2 diabetes model.37 rats were successfully modeled and randomly divided into four groups: diabetic model group(D group),drug group(M group),resistance group(P group),drug + resistance group(MP group).They are all fed with high-sugar and high-fat diets and are free to drink water.After grouping,M and MP groups were treated with 300mg/(kg · d)daily at 9:00 with 7.5 ml/kg double-distilled water to form a metformin suspension for intragastric administration once per day.The NC,D,and P groups received equal amounts of double distilled water daily.P and MP teams started resistance ladder training every day at 14:00.(Climbing ladders are 1.1m in length and 0.18 m in width.Each step is2 cm apart.The ladder is placed at an angle of 80° to the horizontal ground.The top of the ladder is set to a large size.Platforms that can be rested after rats climb up can also be replaced by cages.The training mode is two small cycle trainings,with 1-3 weeks being the first cycle and 4-6 weeks being the second cycle.In the first week,there was no weight-bearing fitness training.Starting from the second week,itstarted with 0% of body weight.It increased daily with a load of 10%of body weight.The final load in the third week was 50% of body weight.At the second cycle,the fourth week for the recovery week for decremental training,and the fifth and sixth weeks repeat for the second and third weeks of training.There is load training from Monday to Friday,and no weight-bearing relaxation ladder training on Saturdays,6 days/week,for a total of 6 weeks;2 groups per day,3 times in each group,1min rest time,and 2min break between groups.)Rats in NC,D,and M groups were free to move in cages without any training.Six weeks after continuous intervention,blood samples and myocardial specimens were anesthetized with 10% chloral hydrate in the abdominal cavity.The volume fraction of myocardial collagen was measured by Masson staining.Serum insulin and myocardial TGF-β1 protein were determined by enzyme-linked immunosorbent assay.Protein expression of MMP-9 and TIMP-1 in left ventricle of rats was detected by Western blotting.Results: After 6 weeks of intervention,the "three more and one less" symptoms,blood glucose levels(P<0.05),and left ventricular TGF-β1(P<0.01)improved significantly in group M diabetic rats;MP group had more obvious control on body weight(P<0.01),serum TC(P<0.05),LDL-C(P<0.05),and HDL-C(P<0.01).Three interventions significantly decreased the expression of MMP-9(P<0.01)and TIMP-1(P<0.05)protein in the heart of type 2 diabetic rats.However,for the myocardial MMP-9 expression,exercise group MP,P group than the M group,the level of decline is more obvious for the myocardial TIMP-1 three groups of intervention effects no significant difference.Conclusions: 1.Three interventions have a certain role in the prevention and treatment of myocardial fibrosis in type 2 diabetes;2.Metformin mainly plays a good role in the control of blood glucose value;3.Resistance to ladder climbing exercise has a good effect in regulating the expression of MMP-9 protein in myocardial tissue and maintaining the dynamic balance of MMP-9/TIMP-1.;4.The combination of the two has significant effects in controlling blood lipids and excessive expression of myocardial collagen. |
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