Sato S M, Frazier J M, Goldberg A M
Exp Neurol. 1984 Sep;85(3):620-30. doi: 10.1016/0014-4886(84)90035-9.
Morphologic alterations of the hippocampal mossy fiber pathway after postnatal lead exposure have been observed in rats. It is hypothesized that lead might perturb zinc pools found in this pathway. To test this hypothesis, rat pups were exposed to lead indirectly by administering 0.2% lead acetate to dams via the drinking water during lactation for 21 days and control litters were maintained on tap water. To evaluate whether or not the effects of postnatal lead exposure were selective for hippocampal zinc pools, the hippocampus was compared with the cerebellum. There were no significant differences between lead-treated and control rats in total zinc content in either the hippocampus or the cerebellum in rats at 30 and 90 days of age. Furthermore, no differences in the subcellular distribution of zinc were observed between control and lead-treated animals. Because the effects on zinc content may be more subtle, the amounts of cytosolic zinc-binding species, isolated using Ultrogel AcA 34 gel chromatography, were measured in control and lead-treated animals. A striking decrease was observed in the amount of zinc associated with one of the cytosolic zinc-binding species, a putative zinc-glutathione complex, shown in previous studies to be the major hippocampal zinc pool. This effect was observed only in the hippocampus of 30-day-old lead-treated rats. By 90 days of age, the effect was no longer present. These data suggest that lead preferentially affects a zinc pool found in the hippocampus and supports our hypothesis that postnatal lead exposure results in an alteration in hippocampal zinc.
在大鼠中已观察到出生后铅暴露后海马苔藓纤维通路的形态学改变。据推测，铅可能会扰乱该通路中发现的锌池。为了验证这一假设，在哺乳期通过饮用水给母鼠施用0.2%的醋酸铅，使幼鼠间接暴露于铅中，持续21天，而对照窝的幼鼠则饮用自来水。为了评估出生后铅暴露的影响是否对海马锌池具有选择性，将海马与小脑进行了比较。在30日龄和90日龄的大鼠中，铅处理组和对照组大鼠海马或小脑中的总锌含量均无显著差异。此外，在对照动物和铅处理动物之间未观察到锌的亚细胞分布差异。由于对锌含量的影响可能更细微，因此使用Ultrogel AcA 34凝胶色谱法分离出的细胞溶质锌结合物种的量，在对照动物和铅处理动物中进行了测量。在与一种细胞溶质锌结合物种（一种假定的锌-谷胱甘肽复合物）相关的锌量中观察到显著下降，先前的研究表明该复合物是海马中的主要锌池。这种效应仅在30日龄铅处理大鼠的海马中观察到。到90日龄时，这种效应不再存在。这些数据表明铅优先影响海马中发现的一个锌池，并支持我们的假设，即出生后铅暴露会导致海马锌的改变。
