Evaluation of Cytotoxicity Attributed to Thimerosal on Murine and Human Kidney Cells

Abstract

Renal inner medullary collecting duct cells (mIMCD3) and human embryonic kidney cells (HEK293) were used for cytoscreening of thimerosal and mercury chloride (HgCl₂). Thimerosal and HgCl₂ acted in a concentration-dependent manner. In mIMCD3 cells the 24-h LC₅₀ values for thimerosal, thiosalicylic acid, 2,2-dithiosalicylic acid, and 2-sulfobenzoic acid were 2.9, 2200, >1000, and >10,000 μM, respectively. The 24-h LC₅₀ value for HgCl₂ in mIMCD3 cells was 40 μM. In HEK293 cells, the 24-h LC₅₀ value for thimerosal was 9.5 μM. These data demonstrate that the higher cytotoxicity produced by thimerosal on renal cells with respect to similar compounds without Hg may be related to this metal content. The present study also establishes mIMCD3 cells as a valuable model for evaluation of cytotoxicity of nephrotoxic compounds.

This study was supported by grants from the National Institute of Environmental Health Sciences Superfund Basic Research Program P42 ES04699, the National Institute of Environmental Health Sciences Center for Environmental Health Sciences P30 ES05707, and the National Institute for Diabetes and Digestive and Kidney Diseases R01-DK59470. However, it has not been subjected to funding agency review and does not necessarily reflect the views of the funding agency.