胰岛素对糖尿病认知功能障碍大鼠EBA表达影响

发布时间：2018-12-27 12:59

【摘要】：目的：通过观察糖尿病认知功能障碍大鼠不同时间、不同部位脑内血脑屏障变化，探讨糖尿病认知功能障碍是否与血脑屏障变化有关，以及胰岛素的干预效果。方法：健康成年雄性SD（Sprague-Dawley）大鼠52只，体重180-250g。随机分为3组：糖尿病组（20只）、胰岛素治疗组（20只）及对照组（12只），每组均以1、3个月为观察点。糖尿病组及胰岛素治疗组大鼠采取单次腹腔注射2%链脲佐菌素（Streptozotocin, STZ）诱导糖尿病模型，72小时后尾静脉取血测定空腹血糖，若空腹血糖11.1mmol/L，且尿糖+++以上者判定为糖尿病造模成功。对照组予单剂量腹腔注射0.1mmol/L柠檬酸-柠檬酸钠缓冲液（pH4.4），血糖正常。胰岛素治疗组每日皮下注射低精蛋白锌胰岛素2-3U，使空腹血糖始终处于正常状态。于1、3个月分批行Morris水迷宫实验后处死大鼠，行免疫组化染色，观察额叶、海马、基底节（即尾壳核）及侧脑室旁白质区内皮屏障抗原（Endothelialbarrier antigen, EBA）表达情况。结果：1、1个月时糖尿病组各脑区内EBA阳性血管与对照组及胰岛素治疗组比较，，部分血管出现管壁边缘硬化、模糊，管腔狭窄、闭塞。各组间血管面积、积分光密度（Integral optical density, IOD）值差异无统计学意义（P0.05）；胰岛素治疗组与对照组比较，差异无统计学意义（P0.05）。 2、3个月时糖尿病组大鼠各脑区内EBA阳性血管管壁硬化、模糊，管腔狭窄、闭塞明显，较1个月时加重，血管面积、IOD值显著减少，差异有统计学意义（P 0.05）；与对照组比较，差异有统计学意义（P 0.05）。 3、3个月时，胰岛素治疗组与对照组及1个月胰岛素治疗组比较，各脑区内EBA阳性血管面积及IOD值均减少，差异有统计学意义（P 0.05）。结论：1、血脑屏障损伤是糖尿病认知功能障碍的原因之一，糖尿病认知功能障碍的严重程度与血脑屏障损伤的程度相关； 2、胰岛素干预可以减轻血脑屏障损伤，但不能阻止其发生、发展，血脑屏障的损伤除糖代谢异常外可能有其他因素参与，需进一步探讨。
[Abstract]:Aim: to observe the changes of blood-brain barrier (BBB) in the brain of diabetic cognitive dysfunction rats at different time and different sites, and to explore whether diabetes cognitive dysfunction is related to the change of BBB and the effect of insulin intervention. Methods: 52 healthy adult male SD (Sprague-Dawley) rats were weight 180-250 g. They were randomly divided into three groups: diabetic group (n = 20), insulin therapy group (n = 20) and control group (n = 12). Diabetic model was induced by single intraperitoneal injection of 2% streptozotocin (Streptozotocin, STZ) in diabetic group and insulin treatment group. Fasting blood glucose (FBG) was measured by tail vein blood samples 72 hours later. If fasting blood glucose was 11.1 mmol / L, the diabetic model was induced by intraperitoneal injection of 2% streptozotocin (Streptozotocin, STZ). The above-mentioned urine sugar was determined to be a successful model of diabetes mellitus. The control group received a single dose of 0.1mmol/L citric acid-sodium citrate buffer (pH4.4) and normal blood glucose. In insulin treatment group, hypoprotamine zinc insulin 2-3 U was injected subcutaneously daily to keep fasting blood glucose in normal state. The rats were killed by Morris water labyrinth test in batches after 1,3 months, and the expression of (Endothelialbarrier antigen, EBA) of skin barrier antigen in frontal lobe, hippocampus, basal ganglia (caudate putamen nucleus) and paraventricular white matter was observed by immunohistochemical staining. Results: 1. Compared with the control group and the insulin treatment group, some of the EBA positive vessels in the diabetic group showed sclerosing, blurring, narrow and occlusive vascular wall at one month. There was no significant difference in vascular area and integrated optical density (Integral optical density, IOD) between each group (P0.05); there was no significant difference between insulin treatment group and control group (P0.05). At 2 and 3 months, the EBA positive vascular wall in the diabetic group was sclerosing and blurred, the lumen was narrow and occlusive, which was more serious than that at 1 month, and the area of blood vessel and the IOD value were significantly decreased (P < 0. 05). Compared with the control group, the difference was statistically significant (P 0.05). At 3 and 3 months, compared with the control group and the 1 month insulin treatment group, the area of EBA positive vessels and the value of IOD in each brain region decreased significantly in the insulin treatment group (P 0.05). Conclusion: 1. The blood-brain barrier injury is one of the causes of diabetes cognitive dysfunction. The severity of diabetes cognitive dysfunction is related to the degree of blood-brain barrier damage. 2, insulin intervention can reduce the blood-brain barrier injury, but can not prevent its occurrence and development, the blood-brain barrier injury may have other factors except abnormal glucose metabolism, need to be further explored.
【学位授予单位】：大连医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R587.1;R749.2

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