Effects of metals Cu, Fe, Ni, V, and Zn on rat lung epithelial cells

Inhalation of combustion-derived particulate matter can have a variety of negative impacts on human health. Metals are known to play a substantial role in these effects, however, the interactions between cellular responses caused by multiple metals is not well understood. The impact of metals (Zn, Cu, Ni, V, and Fe) individually and in combination on a rat lung epithelial cell line (RLE-6TN) was evaluated. Quantifications involved measurement of inhibition of cell culture metabolism (mitochondrial succinate dehydrogenase activity), cell death, mechanisms of cell death, and cytokine secretion. The ranking of metal toxicity based on TC(50) values is V>Zn>Cu>Ni>Fe. Interactions were observed for exposures containing multiple metals: Zn+V, Zn+Cu, Zn+Fe, and Zn+Ni. Zn appears to diminish the negative impact of V and Cu; has an additive effect with Ni, and has no substantial effect on Fe toxicity.