Collins M F, Hrdina P D, Whittle E, Singhal R L
Can J Physiol Pharmacol. 1984 Apr;62(4):430-5. doi: 10.1139/y84-068.
The circadian spontaneous locomotor activity of rats exposed to 0.1 mg lead/kg, po from 3 days until 4 and 6 weeks of age was similar to that of controls. However, hyperactivity during initial hours of recording was observed in rats that were treated with lead (Pb) until 8 weeks of age. When treatment was discontinued for 2 weeks, previously Pb-exposed rats had a tendency to be hypoactive. The elevated locomotor activity in 8-week-old lead-treated rats was not accompanied by any significant changes of noradrenaline levels in the cerebral cortex or hippocampus. Alterations in noradrenaline content of the hippocampus were, however, observed in rats that had been treated with Pb for 4 and 6 weeks. The turnover rate of noradrenaline in the hippocampus was also found to be significantly reduced following treatment for 6 weeks. Regional distribution of Pb in the brains of lead-exposed rats showed a large accumulation of the metal in the hippocampus. The alterations of the noradrenergic function in the hippocampus may be associated with the preferential storage of lead in this region.
从3日龄至4周龄和6周龄经口给予0.1 mg铅/千克的大鼠，其昼夜自发运动活动与对照组相似。然而，在8周龄前接受铅（Pb）处理的大鼠在记录的最初几个小时内出现多动。当停药2周时，先前接触过铅的大鼠有活动不足的倾向。8周龄经铅处理的大鼠运动活动增加，但大脑皮层或海马中的去甲肾上腺素水平没有任何显著变化。然而，在接受4周和6周铅处理的大鼠中观察到海马中去甲肾上腺素含量的改变。在接受6周治疗后，还发现海马中去甲肾上腺素的周转率显著降低。铅暴露大鼠大脑中铅的区域分布显示该金属在海马中大量蓄积。海马中去甲肾上腺素能功能的改变可能与该区域铅的优先储存有关。
