【摘要】 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实施LTP诱导后海马细胞内钙离子浓度([Ca2+]i)和记忆行为的影响。方法从孕前30d始至子代断乳止,对照组(control)与低剂量(用0.2%-Al表示)和高剂量(用0.4%-Al表示)暴露组的母代大鼠分别饮用蒸馏水和浓度为0.015mol·L-1(2g·L-1)、0.03mol·L-1(4g·L-1)的三氯化铝(AlCl3)水溶液;采用原子吸收石墨炉法测定子代鼠的脑铝及血铝含量;以Fura-2/AM为荧光指示剂,测定实施LTP诱导后海马神经元的[Ca2+]i;采用跳台法(即步下试验)测试子代鼠的记忆能力。结果①两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);②与对照组相比,两暴露组海马神经元的[Ca2+]i降低,但0.2%-Al组的差异无显著性(P>0.05),而0.4%-Al组差异有显著性(P<0.01),且0.2%-Al组与0.4%-Al组间的差异亦有显著性(P<0.05);③与对照组相比,两暴露组大鼠步下试验行为测试中跳下平台的潜伏期明显缩短(P<0.01),5min内错误次数明显增加(P<0.01),且两暴露组间的差异亦具有显著性意义(P<0.01)。结论母体不同浓度的慢性铝暴露可损害子代大鼠的记忆能力,其可能的损害机制之一是母体的铝暴露导致海马神经元[Ca2+]i的降低。更多还原

【Abstract】 Aim To investigate the effects of maternal chronic aluminum exposure on memorial behaviour and hippocampal intracellular Ca2+ concentration ([Ca2+]i)on their offspring after the induction of LTP(long-term potentiation). Methods Adult Wistar rats (150~200 g) were exposed to aluminum by drinking distilled water, the concentration of AlCl3 is 0.015 mol·L-1(2 g·L-1) and 0.03 mol·L-1(4 g·L-1) aluminum chloride (AlCl3) solution, respectively, for 30 days prior to mating and during the whole gestation and suckling period. Their offspring were distributed into three experimental groups: control group; two exposed groups (represented by 0.2%-Al and 0.4%-Al ) administrated aluminum exposure ended at postnatal day 21. The brain tissue and blood aluminum levels were measured by Atomic absorption spectrometry (AAS). Memorial ability of the offspring was tested by Step down test.[Ca2+]i was measured by the technique of Fura-2/AM calcium ions fluorescence indicator. Results The mean aluminum content in blood and brain tissue was significantly higher than the control group(P<0.05 or P<0.01). The latencies of step down was significantly decreased, however, the error times of step down was significantly increased in the Al3+ exposed groups (P<0.01) as compared to the control group. The [Ca2+]i reduced in 0.2%-Al exposed group as well as 0.4%-Al exposed group. However, this reduction in 0.2%-Al exposed group was statistically non-significant(P>0.05), but was significantly decreased in 0.4%-Al exposed group(P<0.01). Conclusion Aluminum exposure of maternal rats impaired the memorial behaviour of the offspring, this impairment might be related to the decrease in [Ca2+]i caused by the aluminum exposure.更多还原