| Purpose:In this experiment,by observing the effect of Yitangkang,a traditional Chinese medicine compound,on the expression of vascular endothelial growth factor(VEGF)and pigment epithelial-derived factor(PEDF)in the retina of diabetic rats,the mechanism of the Chinese medicine compound Yitangkang on the retina of diabetic rats was explored.Material and method:Of 80 male SD rats,20 were randomly selected as the blank control group and fed with general food and adequate drinking water,and the remaining 60 were fed with high-fat diet.The type 2 diabetes rat model was replicated by intraperitoneal injection of streptozotocin(STZ)solution in small doses and multiple inductions.The rats were randomly divided into three groups according to blood glucose for different interventions.Rats in the Chinese medicine group were given Chinese medicine compound Yitang Kang 9.45ml/kg was given by gavage,rats in the western medicine group were given 135mg/kg by gavage,and the model group and blank control group were given the same volume of normal saline by gavage,once a day for 12 weeks.Blood glucose and body weight were measured before and at the 4th,8th,and 12 th week after the model was made,and the samples were taken at the end of the12 th week.The HE staining method was used to stain the retinal tissue and observe the tissue morphology;the transmission electron microscope was used to observe the ultrastructural changes of the rat retina;the Western Blot technique was used to detect the expression of VEGF and PEDF protein in the rat retina.Results:1.General conditions of experimental rats: The blank control group rats have nice mental state,normal diet and water intake,and bright and soft fur;after modeling,rats in the model group,traditional Chinese medicine group,and western medicine group appear weight loss,drastically increase their water intake,and urinate.Significant increase and the smell of "rotten apple",and at the same time appearing malaise,slow action or emotional excitement and irritability,hair color withered,eating condition slightly decreased,eyeball color darkened and prominent.Compared with the model group,the symptoms of Yitangkang group and calcium dobesilate group were changed in different degree.2.The weight test results showed that the weight of all rats showed an increasing trend before modeling.Compared with the blank control group,the other three groups were fed with high fat,and the weight of the rats increased significantly(P<0.01);after modeling,The body weight of the rats in the blank control group still showed a gradual increase,and the weight of the other three groups showed a rapid decline compared with the previous ones.On the 4th,8th,and 12 th week of drug intervention,compared with the model group,the weight of the rats in the Chinese medicine group increased and the downward trend was obviously flat,and the difference was statistically significant(P<0.01).3.FBG test results showed that the blood glucose of the rats before modeling was within the normal range;after modeling,compared with the blank control group,the FBG of the other three groups of rats was significantly increased,and the difference was statistically significant(P<0.01);On the 4th,8th,and 12 th week after drug intervention,compared with the blank control group,the FBG of the other three groups of rats was still significantly increased;but compared with the model group,the FBG of the rats in the traditional Chinese medicine group was significantly reduced(P<0.01).4.The results of HE staining showed that the morphology of the retina of the blank control group was not abnormal,the cells of each layer were arranged regularly,the layers were clear,and the structure was neatly arranged.The nuclei of the outer nuclear layer,inner nuclear layer,and ganglion cell layer were clearly stained.Compared with the blank control group,the rat retinal cells in the model group are arranged disorderly,the structure is loose,the thickness is thinner,the number of cells in each layer is reduced,especially the outer nuclear layer has obvious changes,and a series of pathological changes such as vacuoles and edema appear in the cells.Compared with the model group,the state of the retinal tissue of the rats in the Chinese medicine group and the western medicine group was improved,the cells of each layer were arranged relatively regularly,and the thickness of the retina increased.After the treatment,the obvious state was improved,and the number of ganglion cells also showed an increasing trend.The swelling of cell mitochondria was also reduced.5.The observation results under the transmission electron microscope showed that there were no obvious abnormal changes in the ultrastructure of the retina in the blank control group: the capillary basement membrane was complete and continuous,and the nuclei of the outer nuclear layer,inner nuclear layer and ganglion cell layer were clear and large and round.The organelles in the plasm are neatly arranged,and the cells are tightly connected.Compared with the blank control group,the retina of the other three groups showed structural changes:the capillary basement membrane was thickened and incomplete,endothelial cells appeared edema,finger-like protrusions into the vascular cavity,and intracellular mitochondria were swollen.The cristae fell off and the vacuole-like changes were seen,the outer nuclear layer and inner nuclear layer cells were arranged disorderly,and the nucleus was enlarged.Compared with the model group,the ultrastructure of the retina of the rats in the Chinese medicine group and the western medicine group was improved to a certain extent.The thickening of the capillary basement membrane was reduced,the endothelial cell edema and mitochondrial swelling were alleviated,the outer nuclear layer and inner nuclear layer cells were also relatively regular and neat,and the tight junctions between cells were not significantly reduced.6.Western blot results showed that compared with the blank control group,the VEGF levels in the retinal tissues of the other three groups were significantly increased,and the PEDF levels were decreased,and the differences were statistically significant(P<0.01);and with the course of the disease was prolonged,The expression of VEGF protein in the retina of the model group gradually increased,while the expression of PEDF protein gradually decreased.The difference was statistically significant(P<0.01);compared with the model group,the retina of the Chinese medicine group and the western medicine group,the expression level of VEGF in the tissue decreased significantly,while the expression level of PEDF protein increased significantly,the difference was statistically significant(P<0.01);compared with the western medicine group,the expression of VEGF and PEDF protein in the Chinese medicine group had no statistical difference(P> 0.05).Conclusion:1.This experiment uses a high-fat diet plus intraperitoneal injection of streptozotocin(STZ)to establish a type 2 diabetic rat model and further induce a DR rat model.The results prove the general situation of the rat after the model is successfully established.The changes in body weight,blood glucose,and retinal tissue morphology all meet the evaluation criteria of the diabetic retinopathy rat model,and the method is used to successfully replicate the diabetic retinopathy animal model.2.Chinese medicine compound Yitangkang can improve the weight and blood glucose of diabetic rats.3.Chinese medicine compound Yitangkang can improve the degree of retinopathy in diabetic rats.4.The protective effect of Chinese medicine compound Yitangkang on the retina of diabetic rats is achieved by down-regulating the expression of VEGF and up-regulating the expression of PEDF. |
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