目的观察并探讨铝对大鼠血脑屏障的影响。方法健康40d龄SD大鼠80只,按体重随机分到空白生理盐水组、低铝组(Al^3+2.5mg/kg)、中铝组(Al^3+5mg/kg)、高铝组(Al^3+10mg/kg)中,每组20只,腹腔注射无菌AlCl3溶液,造成铝中毒,用Morris水迷宫来检测染毒前后大鼠的学习记忆能力,股静脉注入2%伊文思蓝测定血脑屏障通透性,利用透射电镜观察血脑屏障超微结构和细胞器的变化,蛋白印迹法测紧密连接蛋白occludin的含量变化。结果与生理盐水组相比,中铝组和高铝组大鼠血脑屏障通透性增加,构成血脑屏障重要部分的微血管内皮细胞超微结构发生变化,出现细胞器细胞核的变化,紧密连接蛋白occludin表达显著减少。但各组大鼠水迷宫结果差异无统计学意义。结论短时期铝接触并不能导致大鼠学习记忆能力的改变,但是血脑屏障的超微结构及其通透性均发生了显著变化。
Objective To investigate the effects of aluminum on the integrity of blood brain barrier in juvenile rats. Methods The 40-day old Sprague-Dawley (SD) rats were exposed to aluminium chloride by intraperitioneal injection, at a dose of Al^3+ 0 mg/kg, 2. 5 mg/kg, 5 mg/kg, 10 mg/kg, respectively. Morris water amaze system was used to test the learning and memory ability. The Evans blue content in brain was analyzed after injection. The ultrastructure's change of the blood brain barrier (BBB) was observed with transmission electron microscope. The expression of occluding protein in BBB was determined by Western blot method. Results As compared with control group, the permeability of BBB in mid-level Al and high- level Al was enhanced (P 〈 0. 01 ), the expression of occluding protein was descended ( P 〈 0. 01 ). The ultraztructures of the BBB were changed. No differences between every group on learning and memory ability (P 〉 0. 05 ). Condnsions Short time and low dose of AI might not change the ability of learning and memory-in juvenile rats, however the permeability and ultraztructures of the BBB might be significantly changed.