Toxic Effect of Zinc Ions Is Accompanied by Acidification of the Cytoplasm in Cultured Rat Cerebellar Granule Neurons.

Addition of 0.07 mM zinc ions to the culture medium induced death of cerebellar granule neurons. This was preceded by a decrease in intracellular pH by 0.86±0.12 and an increase in the level of intracellular zinc registered by increasing fluorescence of FluoZin3. However, intracellular acidosis caused by acidification of the culture medium to pH 6.0 was not toxic to neurons, and even significantly increased their survival under the action of zinc ions. In general, the overload of the neurons cytoplasm with zinc ions causes acidification of the cytoplasm, which is probably associated with the activation of Zn2+/H+ exchangers and is a protective mechanism for the neurocytotoxic effect of zinc ions.