Nephrotoxicity of chloroform: metabolism to phosgene by the mouse kidney.

In this investigation, we have attempted to determine whether chloroform (CHCl3)-induced nephrotoxicity might be due to its metabolism to phosgene (COCl2) in the kidney. We have found that kidney homogenates from DBA/2J male mice in the presence of glutathione metabolize CHCl3 to 2-oxothiazolidine-4-carboxylic acid (OTZ). This product appears to be formed by the initial trapping of COCl2 by two molecules of GSH to form diglutathionyl dithiocarbonate (GSCOSG). Kidney gamma-glutamyl transpeptidase can rapidly metabolize GSCOSG to N-(2-oxothiazolidine-4-carbonyl)-glycine which is then hydrolyzed, possibly by cysteinyl glycinase to OTZ. The finding that deuterium-labeled chloroform (CDCl3) was less nephrotoxic and depleted less renal GSH than did CHCl3 suggests that the metabolism of CHCl3 to COCl2 may also occur in the kidney in vivo and lead to nephrotoxicity.