糖尿病大鼠微血管通透性与周围神经病变相关性的实验研究

发布时间：2018-08-11 08:25

【摘要】：目的：探讨实验性糖尿病大鼠坐骨神经微血管通透性变化与周围神经病变的相关性。方法：将雄性SD大鼠(22020g)随机分成实验组（T组，n=60）和对照组（N组，n=12）。采用腹腔注射链脲菌素(STZ)的方法将实验组的60只大鼠全部制备成实验性1型糖尿病大鼠模型。在成模即刻(0w)、成模后2w、4w、8w、12w分别随机选取12只大鼠,分别用T0、T2、T4、T8、T12表示，依次通过伊文思兰灌注在分光光度计下测坐骨神经组织OD值和荧光显微镜下测其荧光量以及坐骨神经的含水量等指标来了解坐骨神经滋养血管的通透性。对其坐骨神经传导速度进行检测，观察大鼠成模后不同时间的病理改变,包括其HE染色及电镜下的超微结构变化。并对坐骨神经组织含水量与NCV、组织EB含量与NCV进行线性相关分析。用免疫组化的方法检测血管内皮生长因子（VEGF）在大鼠坐骨神经上的表达。结果：1.糖尿病大鼠伊文思蓝灌注后，，分光光度计下其坐骨神经OD值从4W开始明显增加（p0.05）；荧光显微镜下观察坐骨神经组织的荧光量可见T4、T8、T12的大鼠神经外膜血管管壁非常强的红色荧光，神经内膜、神经束呈现较强的红色荧光。而与正常对照组相比，糖尿病大鼠8W、12W始出现坐骨神经组织含水量明显增加。2.与正常对照组相比，糖尿病组大鼠从2W开始出现坐骨神经传导速度（Nerveconduction velocity；NCV）明显下降（p0.05）。光镜下可见，糖尿病大鼠的坐骨神经从4w开始出现神经纤维的髓鞘变薄、形态不规则,轴突染色变浅，并伴有轴索萎缩；电镜下观察大鼠坐骨神经的变化可见，T4、T8、T12的糖尿病大鼠均出现了有髓神经纤维髓鞘板层薄厚不一、分离或脱落，局限增厚，结构疏松，且随糖尿病病程的推移，坐骨神经结构病变逐渐加重。3.通过对坐骨神经组织含水量与NCV、组织EB含量与NCV进行线性相关分析，结果显示，在糖尿病的病程中，坐骨神经组织含水量与NCV存在负相关（r=-0.903）；坐骨神经组织EB含量与NCV呈负相关关系（r=-0.799）。4. VEGF在各组大鼠坐骨神经上的表达显示T2、T4、T8的糖尿病大鼠的坐骨神经纤维雪旺氏细胞、轴突以及髓鞘中表达呈阳性，血管壁阳性表达增强。T12糖尿病大鼠的坐骨神经纤维雪旺氏细胞表达呈阳性,而轴索、髓鞘无表达，血管壁表达稍弱，这与N组、T0大鼠类似。结论：1.糖尿病大鼠成模后4周发生了微血管通透性的改变。2.糖尿病大鼠成模后2周出现坐骨神经功能的改变；糖尿病大鼠成模后4周出现坐骨神经结构的改变。3.实验性1型糖尿病大鼠坐骨神经微血管通透性的改变是与坐骨神经结构、功能的变化相关的。4.微血管通透性与坐骨神经病变有相关关系，其可能机制之一是糖尿病诱导血管内皮生长因子VEGF的表达。
[Abstract]:Aim: to investigate the relationship between microvascular permeability of sciatic nerve and peripheral neuropathy in experimental diabetic rats. Methods: male SD rats (22020g) were randomly divided into experimental group (group T) and control group (group N). The experimental model of type 1 diabetes was established by intraperitoneal injection of streptozotocin (STZ) in 60 experimental rats. At 0 w, 12 rats were randomly selected for 2 weeks, 4 weeks, 8 weeks and 12 weeks, respectively. The rats were represented by T0 T2T2OT4T4T8 T12, respectively. In order to understand the permeability of sciatic nerve nourishing vessels, OD value of sciatic nerve was measured with spectrophotometer, fluorescence quantity of sciatic nerve and water content of sciatic nerve were measured under fluorescence microscope. The conduction velocity of sciatic nerve was measured to observe the pathological changes of rat model at different time, including HE staining and ultrastructural changes under electron microscope. The correlation between water content of sciatic nerve tissue and NCVand EB content and NCV were analyzed. The expression of vascular endothelial growth factor (VEGF) in sciatic nerve of rats was detected by immunohistochemical method. The result is 1: 1. The OD value of sciatic nerve in diabetic rats increased significantly from 4W to 4W after perfusing Evans blue (p0.05), and the fluorescence amount of sciatic nerve tissue was observed under fluorescence microscope. The nerve bundle showed a strong red fluorescence in the inner part of the nerve. Compared with the normal control group, the water content of sciatic nerve tissue in diabetic rats increased significantly at 8W and 12W. Compared with the normal control group, the Nerveconduction conduction velocity (nCV) of the diabetic rats decreased significantly from 2 W (p0.05). Under the light microscope, the sciatic nerve of diabetic rats appeared the myelin sheath thinning, the shape irregular, the axon staining shallower and the axonal atrophy from 4 weeks. Observing the changes of sciatic nerve under electron microscope, we can see that the myelin lamellar layer of myelinated nerve fibers in diabetic rats with T4 and T8 and T12 were different in thickness, separated or shed, localized thickening, loose structure, and with the course of diabetes. The pathological changes of sciatic nerve structure gradually aggravation. A linear correlation analysis was made between water content of sciatic nerve tissue and NCV. The results showed that there was a negative correlation between water content of sciatic nerve tissue and NCV in the course of diabetes mellitus (r-0.903). There was a negative correlation between EB content and NCV in sciatic nerve tissue (r-0.799) .4. The expression of VEGF in sciatic nerve showed positive expression in sciatic nerve fiber Schwann cells, axons and myelin sheath of diabetic rats. The expression of Schwann cells in sciatic nerve fibers of T12 diabetic rats was enhanced, but no expression of axonal and myelin sheath was found, and the expression of vascular wall was slightly weak, which was similar to that of T0 rats in N group. Conclusion 1. The change of microvascular permeability occurred 4 weeks after diabetic rat model. 2. 2. The changes of sciatic nerve function were observed in diabetic rats 2 weeks after model formation, and 3. 3 in diabetic rats 4 weeks after model formation. The change of microvascular permeability of sciatic nerve in experimental type 1 diabetic rats is related to the changes of structure and function of sciatic nerve. Microvascular permeability is related to sciatic neuropathy, and one of its possible mechanisms is the expression of vascular endothelial growth factor (VEGF) induced by diabetes.
【学位授予单位】：遵义医学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R587.2;R741

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