Glutamate mobilizes [Zn2+] through Ca2+ -dependent reactive oxygen species accumulation

J Neurochem. 2008 Sep;106(5):2184-93. doi: 10.1111/j.1471-4159.2008.05536.x. Epub 2008 Jul 4.


Liberation of zinc from intracellular stores contributes to oxidant-induced neuronal injury. However, little is known regarding how endogenous oxidant systems regulate intracellular free zinc ([Zn(2+)](i)). Here we simultaneously imaged [Ca(2+)](i) and [Zn(2+)](i) to study acute [Zn(2+)](i) changes in cultured rat forebrain neurons after glutamate receptor activation. Neurons were loaded with fura-2FF and FluoZin-3 to follow [Ca(2+)](i) and [Zn(2+)](i), respectively. Neurons treated with glutamate (100 microM) for 10 min gave large Ca(2+) responses that did not recover after termination of the glutamate stimulus. Glutamate also increased [Zn(2+)](i), however glutamate-induced [Zn(2+)](i) changes were completely dependent on Ca(2+) entry, appeared to arise entirely from internal stores, and were substantially reduced by co-application of the membrane-permeant chelator TPEN during the glutamate treatment. Pharmacological maneuvers revealed that a number of endogenous oxidant producing systems, including nitric oxide synthase, phospholipase A(2), and mitochondria all contributed to glutamate-induced [Zn(2+)](i) changes. We found no evidence that mitochondria buffered [Zn(2+)](i) during acute glutamate receptor activation. We conclude that glutamate-induced [Zn(2+)](i) transients are caused in part by [Ca(2+)](i)-induced reactive oxygen species that arises from both cytosolic and mitochondrial sources.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism
  • Calcium Signaling / drug effects
  • Calcium Signaling / physiology*
  • Cells, Cultured
  • Chelating Agents / pharmacology
  • Cytosol / drug effects
  • Cytosol / metabolism
  • Fluorescent Dyes
  • Fura-2
  • Glutamic Acid / metabolism*
  • Glutamic Acid / pharmacology
  • Intracellular Fluid / metabolism
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Nerve Degeneration / metabolism*
  • Nerve Degeneration / physiopathology
  • Neurons / drug effects
  • Neurons / metabolism
  • Oxidants / biosynthesis
  • Oxidative Stress / drug effects
  • Oxidative Stress / physiology*
  • Polycyclic Compounds
  • Rats
  • Rats, Sprague-Dawley
  • Reactive Oxygen Species / metabolism*
  • Receptors, Glutamate / drug effects
  • Receptors, Glutamate / metabolism
  • Zinc / metabolism*
  • Zinc / pharmacology


  • Chelating Agents
  • FluoZin-3
  • Fluorescent Dyes
  • Oxidants
  • Polycyclic Compounds
  • Reactive Oxygen Species
  • Receptors, Glutamate
  • Glutamic Acid
  • Zinc
  • Calcium
  • Fura-2