Sato S M, Frazier J M, Goldberg A M
J Neurosci. 1984 Jun;4(6):1671-5. doi: 10.1523/JNEUROSCI.04-06-01671.1984.
Previous autoradiographical studies utilizing 65Zn demonstrated an apparent concentration of 65Zn in the mossy fiber boutons of the hippocampus. To examine the speciation of the 65Zn pool found in this neuronal pathway, we investigated the in vivo incorporation of systemic 65Zn into rat hippocampus compared with other brain regions. We were especially interested in kinetically assessing the zinc associated with three previously identified cytosolic zinc-binding species found in the hippocampus. The hypothesis that two of these cytosolic zinc-binding species, a metallothionein-like protein and a putative zinc-glutathione complex, may be responsible for the sequestration of zinc in the hippocampus was tested. It was confirmed that the t 1/2 of hippocampal zinc is longer than other brain regions that were studied. Furthermore, we observed that 65Zn is incorporated into three cytosolic zinc-binding species in the hippocampus as resolved using Ultrogel AcA 34 gel permeation chromatography. One of these species, the putative zinc-glutathione complex, accumulates zinc more slowly than the other species. The data suggest that the putative zinc-glutathione complex may represent an important 65Zn pool in the hippocampus. This finding is in accordance with out hypothesis that a zinc-binding species, specifically, the putative zinc-glutathione complex, may be responsible for the sequestration of zinc in the hippocampal mossy boutons.
以往利用65Zn进行的放射自显影研究表明，海马苔藓纤维终扣中存在明显的65Zn浓度。为了研究在该神经通路中发现的65Zn池的形态，我们研究了全身65Zn在大鼠海马中的体内掺入情况，并与其他脑区进行了比较。我们特别感兴趣的是从动力学角度评估与海马中先前鉴定的三种胞质锌结合物质相关的锌。我们检验了这样一个假设，即这两种胞质锌结合物质，一种金属硫蛋白样蛋白和一种假定的锌-谷胱甘肽复合物，可能是海马中锌螯合的原因。结果证实，海马锌的t1/2比所研究的其他脑区长。此外，我们观察到，使用Ultrogel AcA 34凝胶渗透色谱法解析，65Zn掺入海马中的三种胞质锌结合物质中。其中一种物质，即假定的锌-谷胱甘肽复合物，比其他物质积累锌的速度更慢。数据表明，假定的锌-谷胱甘肽复合物可能代表海马中一个重要的65Zn池。这一发现与我们的假设一致，即一种锌结合物质，特别是假定的锌-谷胱甘肽复合物，可能是海马苔藓终扣中锌螯合的原因。
