The Protective Effects Of STVNa On Diabetic Cardiomyopathy Rats

Diabetes and metabolic syndrome had alarmed global health,moreover diabetes and Obesity had become a global health problem.The persistent diabetes were likely to induce diabetic cardiomyopathy.However,the mechanism of it was still unknown and the effect of regular drug for heart protecting was limited.So,it is urgent to develop a drug to cure this disease particularly.STVNa is sodium formulation of isosteviol prepared for better solubility.The study aimed at investigating whether STVNa could protect diabetic cardiomyopathy in diabetic rats and its possible mechanism.The main research content is as follows:(1)The diabetic rats model was induced by an injection of streptozotocin(STZ).Once the blood glucose concentration was above 11.0 mmol/L,the diabetic model was successful.The rats were randomly divided into 4 groups: normal group,vehicle group,STVNa group(8mg/kg/d),TMZ group(10 mg/kg/d)and weighed each group including food,drink and body regularly.After 12 weeks and 16 weeks,cardiac function indexes of each group were detected by millar system;the arterial pressure was detected by femoral artery catheterization and the heart weight/body weight ratio was calculated.The results showed that after 12 weeks,the blood gulcose concentration of each group all exceeded normal group(above 11 mmol/L);the heart weight/body weight ratio increased and the mean arterial pressure decreased.Both STVNa and TMZ could reduce the heart weight / body weight ratio.After 16 weeks,dose 12 weeks and fed without drug for 4weeks,the mean arterial pressure decreased further and cardiac function deteriorated.Both STVNa and TMZ could increase the mean arterial pressure and recover cardiac function.Moreover,the effect of STVNa was better than TMZ at improving cardiac function.(2)Tissue sections of rat hearts were stained with Haematoxylin and eosin(H&E)to detect the cross-sectional area of cardiomyocytes.Sirius red staining was used to detect the myocardial fibrosis.The results showed that both STVNa and sildenafil could reduce the cross-sectional area of cardiomyocytes and myocardial fibrosis.Nevertheless,the effect of reducing myocardial fibrosis with STVNa was declined after stop dose for 4 weeks.(3)The total RNA of the rats was extracted,reverse transcripted,and detected by PCR.After the analysis of the expression of several signaling pathway(the level of mRNA),the results showed that STVNa inhibited the expression of some genes related to inflammation and oxidative stress.