Comparison of cytotoxicity of cysteine and homocysteine for renal epithelial cells.

Background: Although the cytotoxic effects of cysteine (Cys) on renal cells have been established, the effects of homocysteine (Hcy), which causes endothelial cell dysfunction, have not been well tested. We compared the direct toxicity of Hcy on renal tubular cells to that of Cys and examined the mechanism of cell toxicity.

Methods: LLC-PK1 cells were incubated with test media containing 500 microM Cys or Hcy in the presence or absence of 100 microM copper.