| Objective: To investigate whether the degree of myocardial fibrosis in rats will be aggravated by the presence of diabetes in the state of type 2 diabetes,and the relative amount of telocyte cells in the myocardial interstitium will be aggravated with the increase of myocardial fibrosis in rats.Methods: Male Sprague-Dawley rats were selected and aged 4-6 weeks,divided into type 2 diabetes group and control group.After adaptive feeding for one week,a type 2 diabetes model of SD rats was established by intraperitoneal injection of streptozotocin(STZ)27.5 mg/kg in type 2 diabetic group.After modeling,measured the fasting blood glucose of rats and measured the glucose tolerance by intraperitoneal injection of glucose,to verify whether the type 2 diabetic rats model was constructed successfully or not.After the type 2 diabetes model was constructed,the high-fat and high-sugar diet was continued for 20 weeks to accelerate myocardial fibrosis in diabetic rats.Before the end of the experiment,the body weight,feeding,urine output,blood sugar and other basic conditions of the two groups of rats were measured to estimate whether the diabetes status was stable after successfully established the type 2 diabetes model.The rats were sacrificed after anesthesia,then obtained the myocardial tissue of the rats.The myocardial tissue was stained with Sirius red,Masson's trichrome staining,and type I/III collagen immunohistochemical staining,to identify the degree of fibrosis in rat myocardium.Immunofluorescence technique was used to label myocardial interstitial telocyte cells with double positive markers of CD34 and Vimentin.Counted the relative number of myocardial interstitial telocyte cells per unit area and the relative ratio of telocytes to cardiomyocytes.Compared the difference in the number of telocytes in myocardial interstitial between the type 2 diabetes group and the control group.Results: After model established,compared with the control group,the fasting blood glucose of the type 2 diabetes group increased,reached to the diagnostic criteria for diabetes(fasting blood glucose >7.0mmol/L).The results of intraperitoneal injection of glucose tolerance test(IPGTT)indicated that the glucose tolerance of the diabetic rats is abnormal,and there are typical symptoms of "three more and one less" in the state of diabetic.This indicates that the type 2 diabetes model of SD rats were modeled successfully and the diabetic status remained stable.Myocardial fibrosis staining,compared with the control group,the results of Sirius red staining of myocardial tissue in the diabetic group(4.98±0.33 vs.8.24±0.61,P(27)0.05),type I collagen immunohistochemistry results(892±38vs.5381±634,P(27)0.05)and the immunohistochemical results of type III collagen(2000±256vs.11658±658,P(27)0.05)showed that the degree of myocardial fibrosis was aggravated.Immunofluorescence staining of myocardial interstitial telocyte cells with CD34 and Vimentin antibody,the proportion of myocardial interstitial telocyte cells in the total amount of myocardial tissue cells(0.052±0.010 vs.0.024± 0.003,P(27)0.05)in the diabetic group was lower than that in the control group.Conclusion: In type 2 diabetes,the degree of myocardial fibrosis is aggravated in rats,and the relative amount of myocardial interstitial telocyte cells is decreased with the aggravation of myocardial fibers in diabetic rats. |
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