铝对大鼠海马氨基酸类神经递质含量的影响

Effects of aluminum on amino acid neurotransmitters in hippocampus of rats

目的 从海马氨基酸类神经递质的角度 ,探讨铝的神经毒作用机制。方法 选择雄性SD大鼠 ,按体重随机分 4组 ,在基础饲料中添加氯化铝 ,Al3 + 剂量分别为 0、11 2、5 5 9和 111 9mg/kg体重 ,连续染毒 90d。采用旷场行为和被动回避实验观察神经行为学改变 ,高效液相色谱法测定海马氨基酸类神经递质含量 ,原子吸收法测海马铝含量。结果 与给铝盐前比较 ,大鼠自发活动能力下降 ,被动回避潜伏期缩短。与对照组比较 ,Al3 + 111 9mg/kg体重组海马天门冬氨酸、谷氨酰胺含量显著升高 ,Al3 + 5 5 9和 111 9mg/kg体重组牛磺酸含量显著升高 ,并均与染毒剂量呈明显正相关 ;各剂量组铝含量均显著升高 ,并与染毒剂量呈明显正相关。结论 海马氨基酸类神经递质含量的改变可能是铝神经毒性的重要机制之一。

Objectives To study the effects of long term exposure to aluminum on amino acid tansmitters in hippocampus of rats Methods Sprague Dawley rats were randomly divided into four groups based on their body weight Aluminum chloride was added into diet at doses of 0, 11 2, 55 9 and 111 9 mg/kg BW for 90 days successively Neurobehavioral testing consisted of open field and passive avoidance conditioning The contents of animo acids were detected by HPLC Aluminum was measured by atomic absorption spectroscopy Results The spontaneous motor ability in the open field and the latency of passive avoidance in aluminum treated rats were decreased as compared with the controls In hippocampus, the contents of aspartate(Asp) and glutamine(Gln) were significantly increased at the dose of 111 9 mg Al 3+ /kg BW ( P <0 05, P <0 01), while taurine (Tau) was significantly increased at doses of 55 9 and 111 9 mg Al 3+ /kg BW( P <0 05) as compared with control The increased values of aluminum were significantly related to the dosage of aluminum Conclusion The altered content of amino acid neurotransmitters in hippocampus might be one of the important mechanisms of aluminum neurotoxicity