[Glutamate induces the formation of free radicals in rat brain synaptosomes]

The influence of glutamate and the agonists of its ionotropic receptors on free radical formation in rat brain synaptosomes has been investigated using the fluorescent dye DCFDA. It was shown that glutamate at concentrations of 100 microM and 1 mM increases the synthesis of reactive oxygen species. This phenomenon was eliminated by removing calcium from incubation medium. The addition of NMDA (100 microM) and kainate (100 microM) to a suspension of synaptosomes also led to free radical formation. The influence of glutamate receptor agonists was blocked by the specific antagonists MK-801 and NBQX. Thus, the activation of NMDA and AMPA/kainate receptors can lead to oxidative stress in neuronal presynaptic endings.