亚慢性铝暴露对大鼠认知能力及大脑皮质β-分泌酶-1表达的影响

目的研究铝对大鼠认知能力及大脑皮质β-分泌酶-1(BACE1)蛋白表达的影响。方法健康清洁级SD大鼠32只,按体质量随机分成4组:对照组,0.27、0.54、1.08mg/kg麦芽酚铝染毒组,每组8只,采用腹腔注射方式染毒60d。采用Morris水迷宫测定大鼠学习记忆能力,采用ELISA法测定大鼠皮质BACE1蛋白表达。结果 Morris水迷宫结果显示,亚慢性铝暴露可导致大鼠游泳距离逐渐延长,而在原平台象限游泳时间则明显缩短,与对照组比较差异均具有统计学意义(P<0.05);随染毒剂量的增加,0.54、1.08mg/kg染毒组大脑皮质BACE1含量显著升高,与对照组比较差异具有统计学意义(P<0.05)。结论铝可能通过使大鼠大脑皮质BACE1表达增多而导致其认知能力受损。

Effects of subchronic aluminum exposure on cognition and cerebral BACE1 expression in rats

Objective To investigate the effects of subchronic aluminum exposure on cognition and cerebral BACE1 expression in rats. Methods Thirty-two healthy SD rats were randomly assigned into control group (n=8), 0.27 mg/kg aluminum maltolate exposure group (n=8), 0.54 mg/kg aluminum maltolate exposure group (n=8) and 1.08 mg/kg aluminum maltolate exposure group (n=8), respectively, and were subjected to peritoneal injection for 60 days. The learning and memorizing behaviors were examined by using Morris water maze test, and expression of β-site amyloid precursor protein cleaving enzyme 1 (BACE1) protein in neocortex was determined via ELISA assay. Results It was revealed by Morris water maze test that distance of swimming was gradually extended and duration of swimming at original platform quadrant was markedly shortened as a result of subchronic aluminum exposure when compared with control group (both P<0.05). Considerable increase in BACE1 protein expression in cerebral cortex was associated with elevated dosage of aluminum maltolate (0.54 mg/kg and 1.08 mg/kg) as compared with control group (P<0.05). Conclusion Aluminum may lead to cognitive injury as a consequence of increased cerebral cortex BACE1 protein expression in rats.