The Expression Of Neuroglobin And Vascular Endothelial Growth Factor In The Retinas And Brains Of Diabetic Rats And The Analysis Of The Blood Glucose Changes Of Different Strains Of Mice

Diabetes mellitus is a chronic metabolic disease characterized byhyperglycemia. Diabetic complications and blood glucose metabolism are thehot research topics of diabetes. In this research, we analyze the expressionchanges of neuroglobin (NGB) and vascular endothelial growth factor (VEGF)in diabetic retinopathy and encephalopathy as well as the blood glucosemetabolism features of different mice strains, in order to provide theoreticalbasis for early diagnosis and treatment of diabetic retinopathy andencephalopathy, and also to provide reference data for the establishment ofdiabetes related animal models. The main results are as follows:1. The expression of NGB and VEGF in the retinas and brains of diabetic ratsObjective: diabetic retinopathy and diabetic encephalopathy are two majorneurodegenerative diseases of diabetes mellitus, characterized by neuron damage. Diabetes induced high blood glucose, hypoxia and oxidative stress arethe main reasons that cause tissue damage. NGB is an endogenousneuroprotectant specially expressed in the retina and brain and displays a lot offunctions, including oxygen storage, ROS and RNS scavenging and signaltransduction. For current researches, there are no reports about what role NGBplays in diabetic neural damage. VEGF can protect nerve cells and glial cells,but also promote angiogenesis. The expression changes of VEGF can reflect thedevelopment of diabetic retinopathy. The objective of our research is to studythe expression of NGB and VEGF in diabetic retinas and brains and analyze thefunction of NGB and VEGF in diabetes induced neuron damage and theassociation between diabetic retinopathy and diabetic encephalopathy.Method: health male Sprague Dawley (SD) rats are randomly divided intocontrol groups and diabetes groups and intraperitoneally injected withlarge-dose streptozotocin (STZ) to induce diabetic rat model. The normal ratsand diabetic rats are divided into Group1month, Group3months and Group6months. Sacrifice the rats and fix the eyeballs and brains, then the tissues areembedded in paraffin and cut into slices, Hematoxylin-Eosin (HE) stained andmorphology observed by microscope. And the slices are also treated byimmunohistochemistry reaction to detect the expression of NGB and VEGF inthe retinas and brains.Result:1). The morphology of the retina: pyknotic nuclei are found in partof the retinal ganglion cells (RGC) of3-month diabetic rats and increase withthe development of diabetes. New born blood vessels are found in the layer ofRGC, and cells are sparsely arranged in the inner nuclear layer (INL) and outernuclear layer (ONL) 2). The morphology of the brain: after6months of diabetes, eosin-stainedcytoplasm and pyknotic nuclei are observed in some cells in the retrosplenialcortex (RSC), the cells in the hippocampal dentate gyrus (DG) decrease,accompanied with unclear nucleolus and pyknotic nuclei.3). The expression of NGB in the retina: the expression of NGB in diabeticretina is significantly higher in the INL and ONL, and keeps an upwardtendency with the development of diabetes.4). The expression of NGB in the brain: the expression of NGB in the RSCelevates after1month of diabetes, and the expression of NGB in thehippocampal dentate gyrus is higher after3months of diabetes.5). The expression of VEGF in the retina: the expression of VEGF in thewhole retina of diabetic rats keeps increasing.6). The expression of VEGF in the brain: the expression of VEGF in theRSC is up-regulated in1month diabetes group, without significance, but after3months of diabetes the expression rises significantly. The expression of VEGF inthe hippocampal dentate gyrus is higher in3month diabetes group.Conclusion:1). The expression of NGB and VEGF in diabetic retina andbrain increase with the development of diabetes.2). In diabetic retinopathy, NGB expresses mainly in the layer of RGC, INLand ONL, however, VEGF expresses in the whole retina.3). The expression of NGB increases earlier than VEGF in the diabeticbrain.4). There is a significant negative correlation of the protein level of NGBbetween retina and RSC in the early stage of diabetes.2. The analysis of the blood glucose changes of different strains of mice Objective: in order to provide reference for understanding the difference ofblood glucose metabolism among different mouse strains, we compare theability on regulation of blood glucose changes under food and/or waterdeprivation.Methods: the C57BL/6J mice, BALB/c mice, ICR mice were used in thisstudy. The animals were divided into four groups: control group, fooddeprivation group, water deprivation group and food&water deprivation group.Their blood glucoses were measured within12hours under various stresses.Results and Conclusion: there are different blood glucose regulation patternin different mice strains. The C57BL/6J mouse’s blood glucose level is usuallyhigher than that of the BALB/c and ICR mouse, while the BALB/c mouse’sblood glucose level stays relatively stable, and the ICR mouse has the widestrange of blood glucose level upon these stresses. According to our data, thedifference in blood glucose metabolism in different mouse strains should betaken into consideration in blood glucose related studies for reasonableinterpreting and designing experiments.