On the toxicity of low doses of tetrasodium-ethylenediamine-tetraacetate (Na-EDTA) in normal rat kidney (NRK) cells in culture

The toxicity of tetrasodium-ethylenediaminetetraacetate (Na-EDTA) was investigated in normal rat kidney cells (NRK-52E, American Type Culture Collection) in culture. Cell death and reduced colony-forming ability were observed at Na-EDTA concentrations <100 μM, that is at concentrations lower than that required to chelate all the Ca2+ in the growth medium. No toxicity was observed when cells were exposed to 100 μM Zn- or Fe-EDTA, but the same concentration of Cu-EDTA was as toxic as Na-EDTA. Continuous exposure of the cell cultures to 5 μM Na- or Zn-EDTA for up to 7 weeks yielded no indications of toxicity.