2Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, 119991 Moscow, Russia; E-mail: firstname.lastname@example.org
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Received December 10, 2014
Cultured cerebellar granule neurons (CGNs) are resistant to the toxic effect of ZnCl2 (0.005 mM, 3 h) and slightly sensitive to the effect of kainate (0.1 mM, 3 h). Simultaneous treatment of CGNs with kainate and ZnCl2 caused intensive neuronal death, which was attenuated by external acidosis (pH 6.5) or 5-(N-ethyl-N-isopropyl)amiloride (EIPA, Na+/H+ exchange blocker, 0.03 mM). Intracellular zinc and calcium ion concentrations ([Zn2+]i and [Ca2+]i) were increased under the toxic action of kainate + ZnCl2, this effect being significantly decreased on external acidosis and increased in case of EIPA addition. Neuronal Zn2+ imaging demonstrated that EIPA increases the cytosolic concentration of free Zn2+ on incubation in Zn2+-containing solution. These data imply that acidosis reduces ZnCl2/kainate toxic effects by decreasing Zn2+ entry into neurons, and EIPA prevents zinc stores from being overloaded with zinc.
KEY WORDS: zinc, calcium, kainate, cerebellar granule neurons, acidosis, EIPA