| Objective:The diabetic cardiomyopathy rats modle was established by intravenous injecion of streptozocin. DCM rats were treated by Tempol.To explore the effection and possible mechanism of Tempol on diabetic cardiomyopathy rats by observing the expression of 3-NT and TGF-β1.Methods:1. 42 SD rats( male,200-250g) were fed adaptively for 1 week. 16 of them were randomly elected as normal gloup, while the rest were elected as diabete group that made by injecting STZ(STZ,55 mg/kg).2. 4 weeks later,2 rats of diabete group were killed randomly,then the change of myocardial structure were obserd by HE staining and Masson trichrome staning. If the results of HE staining and Masson trichrome staning show that the myocardial structure of 2 rats had different degrees of degeneration and necrosis, interstitial fibrosis cells, and disordered myocardial tissue were increased. We can consider that diabetic cardiomyopathy modle has been made successfully.3.The 16 normal rats and the rest of 24 modle rats were randomly divided into different groups. The grouping and processing method is as follows:(1)Control +saline group: normal nondiabetic rats received the normal diet,and received the same volume of the solvent for 8weeks.(2)Control+Tempol group: rats treated with tempol in a dose of 18mg/kg/d dissolved in saline by gavage for 8weeks and received the normal diet.( 3) Diabetic group: diabetic rats were just received the normal diet, and received the same volume of the solvent for 8weeks.(4)Diabetic+Tempol group: diabetic rats were reated with tempol in a dose of18mg/kg.d dissolved in saline by gavage for 8 weeks and received the normal diet.4. 8weeks later, the change of myocardial structure were obserd by HE staining and Masson trichrome staning, the expression of 3-NT and TGF-β1 in rat serum were detected by enzyme linked immunosorbent assay(ELISA), the expression of 3-NT and TGF-β1 in rat myocardial were analyzed by immunohistochemistry.Results:1.The diabetic cardiomyopathy rats modle was successfully established by ntraperitoneal injecion of streptozocin.2. The level of random blood glucose in DCM modle group and DCM+Tempol group were significant higher than control group(P <0.05), but The differences of random blood glucose levels between DCM modle group and DCM+Tempol group were not statistically significant at week(P> 0.05); at the end of the test, the weight of DCM group and DCM+Tempol group were significantly lower than control group(P <0.05), however, the level of weight decling in DCM+Tempol group were lower than DCM group(P <0.05); No signifant differences were found between NC+NS control group and NC+Tempol group in the levels of weight and random blood glucose(P> 0.05).3.The microscope results showed that: the fracture of heart in control rats showed normal histological structure of the cardiac tissues,but the results of DCM group show that the myocardial cells were disordered arrangement, heart of DCM group rats exhibits vaculations of cardiac myocytes associated with inflammatory cells infiltration and intramyocardial, and had different degrees degeneration,necrosis,intramyocardial edema, however, the demage of cardiac myocytes of DCM+Tempol group were alleviated; Masson trichrome staning results show that the myocardial structure of control group were normal;the myocardial structure of DCM group and DCM+tempol group exhibits interstitial fibrosis cells control with control group, The leve of fibrillation in DCM+Tempol group rats heart were alleviated than DCM group.4.The results of nzyme linked immunosorbent assay(ELISA) showed that: the density of 3-NT in the NC+NS group, NC+Tempol group, DCM group, DCM+Tempol group were 79.11±25.37nmol/L, 99.98±24.99nmol/L, 371.56±95.64nmol/L,246.31±81.37nmol/L; the density of TGF-β1 were 107.02±35.53pg/ml,136.69±19.68pg/ml, 347.07±57.85pg/ml, 218.67±26.62pg/ml; it is significant that the expression of 3-NT, TGF-β1 in DCM group, DCM +Tempol group rats’ blood plasms were higher than control group, the differences was statistically significant(P<0.05); the expression of 3-NT, TGF-β1 in DCM+Tempol group rats’ blood plasms were lower than DCM group(P<0.05); the differences of the expression of 3-NT, TGF-β1between the NC+NS group and NC+Tempol group were no significant(P> 0.05).5. The expression of 3-NT and TGF-β1 in rat myocardial analyzed by immunohistochemistry showed that: the expression of 3-NT in the NC+NS group,NC+Tempol group, DCM group, DCM +Tempol group were 2512.38±1636.43 、2935.69±1492.17、11684.89±2590.43、5625.41±1501.94; the expression of TGF-β1were 894.67±152.29、1001.72±215.04、8805.64±2893.75、4707.79±1121.13; it is obvious that the expression of 3-NT, TGF-β1 in DCM group, DCM +Tempol group rats’ myocardium were higher than control group, the differences was statistically significant(P<0.05); however, the expression of 3-NT, TGF-β1 in DCM+Tempol group rats’ myocardium were lower than DCM group(P<0.05); No signifant differences were found between NC+NS control group and NC+Tempol group in the expression of 3-NT, TGF-β1 in myocardium(P> 0.05).Conclusion:1. The diabetic model can be found by intraperitoneal injecion of streptozocin,long-term high blood sugar may result myocardial injury.2. Increased expression of 3-NT, TGF-β1 result from hyperglycemic state oxidative stress may lead to myocardial cell necrosis and fibrosis, and this pathologic processes maybe involved in the occurrence of DCM.3.Tempol had no significant effect on normal rat’ myocardium, and Tempol plays its role on DCM rats’ myocardial protection perhaps by inhibiting oxidative stress reaction and reducing the expressions of 3-NT, TGF-β1. |
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