Effects Of Pdb On The Role And Mechanisms Of Diabetic Rats

ObjectiveTo investigate the effect of Potentilla Discolor Bunge(PDB) on the morphosis and function of vascular endothelial cells and the function of pancreatic islet B cells, and to explore the mechanisms of PDB on diabetic mellitus and its vascular complication.MethodsForty adult Wistar rats weighing 200~250g were bought a week before the experiment. All the animals were housed in quiet and warm environment (room temperature 18~25℃), away from highlight. The rats were first randomly assigned to two groups: one for control(n=10), the other one for diabetes, in which each rat was injected alloxan intraperitoneally. Then the diabetic rats were randomly divided into three groups.- diabetic control group, experimental control group(Gli~ benclamide group) and the PDB group(n=10).The control animals underwent no treatment and the diabetic control animals were left untreated , while the experimental control animals were administered with Glibenclamide(0. 25mg/kg/d) intragastricly and the PDB rats were intragastricly administered with herb tea of PDB(15g/kg/d) for 4 weeks continuously. The animals of experimental control group and the PDB group were under investigation during the experiment.The blood glucose levels of all the rats was measured by the SureStep blood glucose meter. The pancreatic islet cells were stained with aldehyde-fuchsin and the histological changes of vascular endothelial cells were assayed by using stretched preparation method. The activity of nitric oxide synthase(NOS) in the aorta of all the animals was detected by using immunohistochemical method.Results1. Weights of body: In the diabetic rats, the body weight wassignificantly decreased(P<0.05), while that of the Glibenclamide and PDB rats was significantly increased. The difference between the body weight of rats before and after the experiment was very obvious (KO. 01), but no marked difference was observed between the Glibenclamide rats and the PDB rats.2.Blood glucose levels: In the diabetic control rats, the blood glucose level was continuously elevated during the experiment. Both Glibenclamide and PDB can reduce the blood glucose remarkably, and the effect of PDB on blood glucose outweighed that of Glibenclamide notably(P<0.01).3.The morphology of islet Bcells: Islets of the control rats were spherical or elliptical, and the border was very clear. B cells were located in the center of the islets, with round nucleus in the center of cells. In the diabetic rats, borders of islets were not very clear, the number of B cells was reduced significantly* and, swelling and necrosis was usually observed. The number of B cells in Glibenclamide rats was moderately reduced, but much more than that of the diabetic rats. Borders of pancreatic islets in the PDB rats were very distinct, the number of B cells was a little smaller than that of the control rats, and the density of cells was much higher than that of the diabetic rats. The structure of cells was complete, and no swelling and necrosis was observed.4. The morphosis of VEC: In control rats, the membrane of vascular endothelial cells was moderately denticulate which had clear and continuous borders, and the nucleus was located in the center of cells. But in diabetic rats, the membrane was not continuous, with membrane stiffening or thickening denticulate. The denticulate argyrophil lines between vascular endothelial cells are thickened and parce, but the interruption of continuity is not present. The shape of VEC in the PDB rats is approximate to that of the control rats.5. The activity of NOS in VEC: The VECs of control rats were stained dark blue, the membrane,plasma , nucleus and the border of each cell were displayed clearly. In the diabetic rats, the membrane of VECs was not clearly displayed and the plasma was light-stained. The optical density of VEC in the diabetic rats was much lower than that of thecontrol rats(P<0. 01).In the Glibenclamide rats, the membrane, plasma and nucleus were clearly displayed, the border of each cell was clear and the plasma was stained much lighter than the cont...