The Expression And Correlative Of VEGF And ICAM-1 In Inner Ear Of Diabetic Rats

Objective: Microangiopathy in inner ear is one of chronic compliactions of diabetes.The mechanism of diabetic microangiopathy were formed a variety of theories: basically had the non-enzymatic reations and polyols pathways doctrine, diacylglycerol protein kinase C system (Diacylglycerolprotein kinase C, DAG - PKC system) theory and oxidative stress, etc, so far, has not been formed identity of views. Recently, some researches had found that inflammation process of abnormal activation was the main mechanism of diabetes microvessel damage, sparking diabetes-related complications in inflammatory reaction process generated inflammatory factors were the key factor inflammatory damage, but its blood vessels and tissue damage mechanism remains to be unknow. VEGF also call vascular permeability factor, it is a group of molecular weight in 34 000 ~ 45 000 of homologous dimer glycoprotein, is endothelial cells of specific mitogen, has the formidable factorp vascular fully ability and promote angiogenesis effect.VEGF with different may pass receptors, activate different signal transmission system and exert its diverse biological function。The main biological function of VEGF had such as factorp vascular endothelial cell proliferation and migration, promote angiogenesis, and increase vascular permeability effect. The intercellular adhesion molecules - 1 (ICAM - 1), a cell surface expression glycoprotein ,which has mediated cells or cell with extracellular matrix interactions. ICAM - 1 plays an important role in Various pathophysiological process which through its receptor mediated cells adhesion, signal, cell functions, the body of embryonic development, maintennace of normal tissue structures, inflammation , immune response, wound repairation, blood coagulation , thrombosis, tumor invasion and metastasis etc. In inflammation and autoimmune response process of the inner ear, intercellular adhesion molecules - 1 (ICAM - 1) expressed heighten in a variety of factors stimulating, that induce mononuclear macrophages adherent to the vascular endothelial cells and crosses vessels wall wander to specific inflammatory reaction area。It can provide theory basis to explore the pathogenesis of diabetes deafness,prophylaxis clinical and delayed diabetes deafness to investigate vascular endothelial growth factor's (VEGF) and intercellular adhesion molecules - 1's (ICAM - 1) expresion and correlation in diabetes capillary pathological changes of the inner ear.Methods: Adopt vscular endothelial growth factor and intercellular adhesion molecules - 1 immunohistochemical inspection and cochlear blood capillary wall thickness of light microscopy, to analyze VEGF and ICAM - 1 in diabetes inner ear microvascular lesions expression and its correlation. Specific steps are as follows:(1)Animal selection and processing :Choose white female healthy wister rats 48 (hebei medical university animal experiment center provides), shoud 2.5-3 months, weight 180 ~ 220g; Must auricle reflection sensitive and otoscopy observation eardrums integrity. According to the original weight by small to big Numbers, randomly divided into two groups, group one of control group (CG) in ordinary feed, groups two for diabetes mellitus (DM) with high fat, high in sugar, with chain feed urine carrizo bacteria hormone (STZ) 55mg/kg intraperitoneal injection, build diabetes model, note medicine after animals diabetes , blood sugar mmol/L > 16.65 to build mode of success. Healthy rats one-time intraperitoneal injection water-volume excluding STZ of 0.1 mol/L citric acid buffer a as a comparison, later in ordinary feed. To build model, will succeed timing starts diabetic rats were randomly divided into diabetes 0 weeks (DM0), diabetes 4 weeks (DM4), diabetes 8 weeks (DM8), diabetes 12 weeks (DM12) and the normal group is divided into normal group 0 weeks (CG0), the normal group 4 weeks (CG 4), the normal group of 8 weeks (CG 8), the normal group 12 weeks (CG 12), respectively on 0 weeks, 4 weeks, 8 weeks, 12 weeks take diabetes groups (DM) and control group (CG) 6 rats did take out after general anesthesia cochlear into fixed in 4% polyphosphate formaldehyde, 4 degrees cross-matched set aside. (2)Immunohistochemical experiment : Take each rat's ears in EDTA fluid demineralization 10 days, gradient alcohol dehydration lines paraffin embedding, ultrathin slicing machine sliced lookahead immunohistochemical experiment, specific steps in accordance with the kit .(3)Light microscopy (4)Statistic analysis.Result:1 Rats generally:Healthy rats generally good, move freely, eating and drinking water situation without opparent change, the weight increases continuously ; Diabetic rats appeared eating increase, water increases, discharge increase, weight loss and other typical performance of the diabetes. After repeated test, control blood sugar are stable in the normal range, diabetics are markedly elevated blood sugar, explain made model success.2 Vascular wall thickness changes:Two groups of rats in each time stria capillary wall thickness measurement results to x_±s, The normal group 0 weeks vascular wall thickness average 0.094 u m±0.022 um, 4 weeks for the average 0.097 um±0.021 um, eight weeks with an average 0.10 um + 0.01 um, 12 weeks for an average of 0.189 um±0.03 um .But the group with diabetes vascular wall thickening, obviously group with diabetes 0 weeks average vascular wall thickness of 0.11 um±0.01 um, 4 weeks for the average 0.145 um±0.023um, 8 weeks for 0.176 um±0.03 um, 12 weeks for an average of 0.189 um±0.03 um. By statistical analysis,Two groups of vascular wall thickness with significant difference (P < 0.05), namely diabetics vascular wall thickness are higher than normal group, and the duration extension vascular wall thickness increases gradually.3 Vascular endothelial growth factor expression:The control group, VEGF in stria, spiral ligament, spiral machine, screw axis and spiral ganglion cells has a faint expression.In diabetic rats, VEGF in stria, spiral ligament, spiral ganglion cells express the obvious enhancement, and the duration extension express mild increase gradually, mainly in the cytoplasm expression. Diabetics and comparison between the normal group express (P < 0.05) greup.In diabetic rats ,VEGF expression and hemal wall thick do a correlation analysis between (r = 0.759 positively correlated, p < 0.01).4 Intercellular adhesion molecules - 1 expression :The normal group ICAM - 1 for the expression of weak positive, mainly express parts have the spiral ligament and outside lymphatic interval skin have weak (+) ICAM - 1 dyeing.Diabetics ICAM - 1 for the expression with the duration extension express parts increase and positive is more and more strong, performance for weak positive, position, strong positive, mainly express parts have the screw axis vein and backflow of small vein, spiral ligament, especially screw axis vein and backflow venules dyeing is stronger. Mainly in the cytoplasm expression. Diabetes group and is different between the normal group (P < 0.05), and blood vessel wall thickness do a correlation analysis, there is a correlation between (R = 0.729, P < 0.01).Conclusion1 To STZ 55mg/kg one-time intraperitoneal injection wister female rats successfully establish similar human of type 2 diabetes in the rat model ;2 The microangiopathy in inner ear of diabetic rats include that the basement membrane of capillary thicken;3 The expression of VEGF enhance in diabetic rats inner ear, and with the basement membrane of capillary are positively correlated;4 The expression of ICAM-1 enhance in diabetic rats inner ear, and with the basement membrane of capillary are positively correlated;5The expression of VEGF and ICAM-1 in inner ear of diabetic rats are correlation ,VEGF may have certain of the regulation effects to ICAM-1.