[Back to Issue 8 ToC] [Back to Journal Contents] [Back to Biochemistry (Moscow) Home page]

Acidosis and 5-(N-ethyl-N-isopropyl)amiloride (EIPA) Attenuate Zinc/Kainate Toxicity in Cultured Cerebellar Granule Neurons

E. V. Stelmashook1*, S. V. Novikova1, G. A. Amelkina2, E. G. Ivashkin1, E. E. Genrikhs1, L. G. Khaspekov1, and N. K. Isaev1,2*

1Research Center of Neurology, Russian Academy of Medical Sciences, 125367 Moscow, Russia; E-mail: estelmash@mail.ru

2Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, 119991 Moscow, Russia; E-mail: isaev@genebee.msu.ru

* To whom correspondence should be addressed.

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

DOI: 10.1134/S000629791508012X