Comparison Of Anti-atherosclerotic Effects Between Metformin And Gliquidone In SD Rats With Type2Diabetes Mellitus

Objective:To examine and compare the effects of metformin and gliquidone on atherosclerotic lesions in streptozotocin-induced diabetic rats using hematoxylin and eosin (H&E) staining.Methods:Fifty male Sprague-Dawley rats (age,8weeks; weight,180-200g) were randomly divided into normal control group (NC) and diabetic model group. NC rats were fed with regular chow for2weeks and received a vehicle. Rats in all other groups were fed with a high-fat diet for2weeks, then streptozotocin was injected intraperitoneally at a dose of35mg/kg. After succeeded, the model groups are divided into diabetes mellitus group (DM), metformin group (MET) and gliquidone group (GLI). After an additional5weeks, taken the tail blood for biochemical determinations. Then rats in the NC and DM groups were administrated with normal saline, while rats from the MET and GLI groups were administrated with metformin (300mg/kg) or gliquidone (30mg/kg), respectively. All medicines were given via intragastric administration for8weeks. Serum samples were collected from inferior vena cava for biochemical determination The aortic arch was isolated from diabetic rats and was assessed by pathological sectioning using H&E staining.Results:There were no significant differences in baseline characteristics between GLI and MET groups. FBG decreased significantly in the GLI group and MET group (16.97±5.90before treatment versus10.64±2.36after treatment,P=0.008;18.52±6.78before treatment versus11.30±3.29after treatment, P=0.010, respectively). Serum TG and LDL-C decreased in the MET group (0.65±0.17before treatment versus0.47±0.16after treatment, P=0.024;0.46±0.09before treatment versus0.30±0.07after treatment, P=0.000, respectively), but remained unchanged in the GLI group. Serum HDL-C was increased (0.83±0.16before treatment versus1.01±0.15after treatment, P=0.015) in the MET group, while HDL-C was not increased in the GLI group. Weight in the MET group decreased a little (P=0.039). There were no significant changes in weight, TG, TC, HDL-C and LDL-C in the GLI group (P>0.05). Weight in the DM group did not change significantly (318.60±79.08vs324.98±72.59,P=0.608). Weight in the NC group increased significantly (398.28±61.00vs441.68±77.74, P=0.000). Under light microscopy, no changes were observed in the aortic wall structure of each layer; the intima was smooth and the membrane elastic fibers were normal in the NC group. In the DM group, the aortic wall structure was unclear, the intima was thickened and filled with foam cells, and membrane elastic fibers collapsed. The aortic intima of the MET and GLI groups was smoother compared with the DM group, but the endothelial structure of the MET group was closer to that of the NC group.Conclusion:We found both metformin and gliquidone have anti-atherosclerotic effects, but the endothelial structure of the MET group was closer to that of the NC group. These data may have important implications for the treatment of patients with type2diabetes mellitus.