长期摄铝对大鼠海马铝、铁、锌含量和脂质过氧化的影响

Effects of aluminum intake on the content of aluminum, iron, zinc and lipid peroxidation in the hippocampus of rats

为研究长期摄铝对大鼠海马铝、铁、锌、铜含量和脂质过氧化的影响 ,进一步探明铝的神经毒作用机理 ,选择雄性SD大鼠 ,按体重随机分为对照组和 3个实验组 (低铝、中铝、高铝组 ) ,实验组在基础饲料中添加氯化铝 ,使Al3+ 剂量分别为 11 2、5 5 9和 111 9mg kgBW ,连续染毒 90天。采用旷场行为实验和被动回避实验观察神经行为学改变 ;原子吸收法测定铝、铁、锌、铜含量 ;分光光度法测定超氧化物歧化酶 (SOD)和谷胱甘肽过氧化物酶 (GSH Px)活性及丙二醛 (MDA)含量。结果显示 :与对照组比较 ,实验组大鼠自发活动能力下降 ,被动回避潜伏期缩短 ;大鼠海马铝含量升高 ,铁、锌含量下降 ;SOD和GSH Px活性下降 ,MDA含量升高。提示长期摄铝可致大鼠海马铝富集并干扰铁、锌的正常分布 ,抗氧化酶活性降低 ,脂质过氧化水平升高。海马富集铝以及铁、锌含量的变化和海马氧化损伤可能是导致铝的神经毒性的重要原因之一。

Effect of long term exposure to aluminum on the content of aluminum, iron, zinc, copper and the lipid peroxidation in hippocampus was studied. Sprague Dawley rats were randomly divided into four groups by body weight. Aluminum chloride was added to diet at doses of Al 3+ 0, 11 2, 55 9 and 111 9 mg /kg BW for successive 90 days. Neuro behavioral tests consisted of open field and passive avoidance conditioning were performed. SOD and GSH Px activities and MDA levels were detected by spectrophotometry. The values of aluminum, iron, zinc and copper were measured by atomic absorption spectroscopy. The spontaneous motor ability in the open field and the latency of passive avoidance were decreased as compared with the controls. The concentration of aluminum was increased and iron and zinc were decreased copper was not changed significantly; the activities of SOD and GSH Px were reduced, while the value of MDA was increased in hippocampus. The results suggested that long term aluminumexposure could lead to high accumulation of aluminum in hipocampus, which could disturb the normal distribution of iron and zinc, decrease the activities of antioxidase and increase the level of lipid peroxidation. Accumulation of aluminum and accompany with reduction of iron, zinc in hippocampus and oxidative damage to hippocampus might interpret the neurotoxicity of aluminum.