母体慢性铝暴露对子代鼠海马LTP的损害作用

目的探讨母体于孕前、孕期和哺乳期不同浓度的铝暴露对子代大鼠海马CA3-CA1通路诱导的LTP的影响。方法从孕前30d始至子代断乳止,对照组饮用蒸馏水,低剂量(0.2%Al)和高剂量(0.4%Al)暴露组的母代大鼠分别和铝离子(Al3+)浓度为0.074mol·L-1(2g·L-1)、0.148mol·L-1(4g·L-1)的三氯化铝(AlCl3)蒸馏水溶液;采用石墨炉原子吸收法测定子代鼠的脑铝及血铝含量;采用细胞内记录方法测定子代鼠海马CA3-CA1通路诱导的LTP。结果两暴露组大鼠的血铝和脑铝平均含量明显高于对照组(P<0.05及P<0.01);高频刺激后,两暴露组群体锋电位(PS)幅值增强率(相对于基线值的百分数)逐渐减小,与对照组相比差异非常显著(P<0.01),但两铝暴露组之间差异不显著。结论母体不同浓度的慢性铝暴露可使PS幅值增强率减小,提示铝暴露损害了子代大鼠LTP的诱导与维持。

Impairment of Maternal Chronic Aluminum Exposure on Hippocampal LTP of Offspring in Rats

Objective To investigate the impairment of the maternal chronic aluminum exposure on LTP （longterm potentiation） in hippocampal CA3 to CA1 of the offspring. Methods Adult Wistar rats （150-200g） were divided into control group（drinking distilled water） and two exposed groups{drinking AlCl3,0.074mol · L^-1 （2g · L^-1） and 0.148mol · L^-1 （4g · L^-1） respectively} for period from 30 days before mating to the end of suckling. The brain tissue and blood aluminum levels of the spring were measured by atomic absorption spectrometry （AAS）. LTP in hippocampal CA3 to CA1 of the offspring was determined by intracellular recordings. Results The enhancement rate of population spike（PS） amplitude reduced evidently after high-frequency stimulation （HFS） in exposure groups than in control group （ P〈0.01 ） ,but with not significant difference between the two exposed groups（p〉0.05）. The mean aluminum content in blood and brain tissue of spring was significantly higher in two exposed groups than in control（P〈0.05 or P〈0.01）. Conclusion Aluminum exposure of maternal rats impaired the induction and maitainence of hippocampal LTP of the offspring.