Sulzer D, Piscopo I, Ungar F, Holtzman E
Department of Biological Sciences, Columbia University, New York, New York 10027.
J Neurobiol. 1987 Sep;18(5):467-83. doi: 10.1002/neu.480180507.
We have observed electron dense deposits dependent on incubation of aldehyde-fixed tissues with lead ions within synaptic vesicles of several types of neurons that differ in the neurotransmitters utilized and in the secretory granules of the adrenal medulla. Evidently, vesicle components that can interact with lead ions are widespread. A plausible explanation for the occurrence of the deposits is the presence of anionic binding sites within the vesicles. This would agree well with other biochemical, cytochemical, and immunocytochemical evidence, such as that indicating the presence of sulfated macromolecules in certain synaptic vesicles. Anionic binding sites could play significant roles by participating in processes such as Ca2+ storage, stabilization of pH gradients, or the control of osmotic phenomena.
我们已经观察到，在几种类型的神经元的突触小泡以及肾上腺髓质的分泌颗粒中，醛固定组织与铅离子孵育后会出现电子致密沉积物。这些神经元在所用神经递质方面存在差异。显然，能够与铅离子相互作用的囊泡成分广泛存在。沉积物出现的一个合理原因是囊泡内存在阴离子结合位点。这与其他生化、细胞化学和免疫细胞化学证据非常吻合，比如表明某些突触小泡中存在硫酸化大分子的证据。阴离子结合位点可能通过参与诸如钙离子储存、pH梯度稳定或渗透现象控制等过程发挥重要作用。
