Objective: To study the protective effect of the total flavones of buckwheat flowers and leaves (TFBFL)on the myocardial injury of the type 2 diabetic rats,and to clarify its mechanism.Methods:The diabetic rat models were established by intraperitoneally injecting streptozotocin (STZ)and taking high-fat diet.The model rats were divided into diabetic model (DM)group and TFBFL treatment (TFBFL)group,while normal control group was set up, 10 rats per group.The rats in TFBFL group were administered with 200 mL· kg-1 · d-1 TFBFL,while the rats in other two groups were given with normal water (10 mL·kg-1 ·d-1 )instead.The rats in various groups was administered once a day for 8 weeks.The body weight (BW),heart weight index (HWI), level of fasting blood glucose (FBG)and cardiac function indexes (HR,LVSP,LVEDP and ± dp/dtmax )of the rats in various groups were measured.The myocardial tissue morphology of the rats in various groups was evaluated by electron microscope and the collagen levels in myocardium tissue of the rats in various groups were observed by Masson staining.The expression levels of TGF-β1 protein in myocardium tissue of the rats in various groups were detected by Western blotting method.Results:Compared with normal control group,the HWI,FBG and LVEDP levels of the rats in DM group were increased (P <0.05 or P <0.01),and the BW, HR,LVSP and ±dp/dtmax level in DM group were decreased (P <0.05 or P <0.01).Compared with DM group,the FBG and LVEDP level in TFBFL group were decreased (P < 0.01 ),and the HR,LVSP and ± dp/dtmax level in TFBFL group were increased (P < 0.05 or P < 0.01 ); but the BW and HWI level in TFBFL group had no significant difference compared with DM group (P >0.05).The Masson staining results showed the morphology of myocardium tissue of the rats in TFBFL group was improved and the collagen level was decreased. The Western blotting results suggested that the TGF-β1 protein expression level in myocardium tissue of the rats in DM group was significantly increased compared with normal control group (P < 0.05),and the TGF-β1 protein expression level of the rats in TFBFL group was decreased compared with DM group (P <0.05).Conclusion:TFBFL exerts a certain protective effect on the myocardial fibrosis of diabetic rats through inhibiting the TGF-β1 expression in myocardium tissue.

Objective:To study the influence of rutin in the morphology of renal tissue of the diabetic mice induced by streptozotocin(STZ), and to clarify the effect of rutin on the kidney tissue damage.Methods:Twelve mice of the total 70 Kunming mice were used as normal group, the other were used to estabish type 1 diabetes mouse models by intraperitoneally injected with STZ (62.5 mg·kg-1), once daily for 5 d.The successfully established model mice were randomly divided into model group,low dose (50 mg·kg-1)of rutin group, high dose (100 mg·kg-1) of rutin group and irbesartan group (45 mg·kg-1).The mice in model group and normal group were given the carboxy methyl cellulose(CMC) and the other mice were given drugs by intragastric administration once daily for 8 weeks accordingly.The weight and blood glucose of the each mouse were determined.Full automatic biochemical analyzer was used to detect the levels of serum creatinine (Cre) and blood urine nitrogen (BUN) of the mice , and the kidney index was calculated.The morphology of renal tissue was observed by HE staining, Masson staining and electron microscope.Results:After injection of STZ,the model success rate was up to 98%.Compared with normal group, there was no significant difference in the weight of the mice in other groups before administration(P>0.05).After administration of rutin, the weights of the mice in model group, low dose of rutin group, high dose of rutin group and irbesartan group were significantly decreased (P<0.05).Compared with model group, the levels of blood glucose of the mice in low and high doses of rutin groups were significantly decreased(P<0.05);the levels of Cre and BUN were significantly reduced (P<0.05);the kidney index of the mice in high dose of rutin group was significantly decreased (P<0.05).Compared with normal group,the kidney tissue of the mice in model group was seriously damaged;glomerular was weaked, the kidney tissue fibrosis was serious, glomerular basement membrane was diffusely thickened and foot process was coalesced or overgrow.Compared with model group,the degree of injury of the mice in low and high doses of rutin groups were significantly improved, especially in high dose of rutin group.Conclusion:Rutin can improve the renal function of diabetic mice induced by STZ and reduce the degree of renal tissue damage in the diabetic mice

Aim To introduce an improved method of Langendorff perfusion of the isolated rat heart that is easy to determine the termination of digestion.Methods Hearts were excised quickly from anesthetized SD rats.After the perfusate was free of blood,the solution was changed to perfusion buffer(0.6% Collagenase B,0.6% BSA,30 ?mol?L-1 Ca2+ in Tyrode solution)at 37℃.Hearts were isolated by traditional and improved Langendorff perfusion.Individual myocardial cell was measured by video-based motion edge-detection system(IonOptix,USA).Results One group of heart was digested by traditional Langendorff perfusion for 13~16 min.The termination of digestion could not be judged properly by this method.The nature and quality of the cardiocytes were various.The cardiocytes could not keep their survival and viability when exposed to Tyrode Solution with 1.8 mmol?L-1 Ca2+.Another group was digested by improved Langendorff perfusion.More than 80% survival cardiac ventricle myocytes could be obtained by improved Langendorff perfusion.Moreover,about 50% cardiac myocytes exposed to Tyrode solution with 1.8 mmol?L-1 Ca2+ could retain rod-shaped and be used to contraction research.The contraction of cardiocyte was stabile within 1 000 s.Conclusion Cardiac myocytes disassociated from improved Langendorff perfusion can be used in these studies of detecting contraction and relaxation.This method is economical and easy to control.The beginners are able to acquire the technological method over a short-term practice.