Involvement of cytochrome P4502E1 in the toxicity of dichloropropanol to rat hepatocyte cultures.
Hammond, A.H. and Fry, J.R.
Toxicology, 118(2-3), 171-179 (1997).
Hepatocytes were isolated and cultured from untreated rats and rats treated with isoniazid to induce cytochrome P4502E1. Isoniazid selectively increased p-nitrophenol hydroxylase activity in 2-h cultures, and increased the toxicity of both 1,3- and 2,3-dichloropropanol. Isoniazid also increased the rate and extent of glutathione depletion by the dichloropropanols. There was no effect of isoniazid on the toxicity of 1,3-dichloroacetone, precocene II or allyl alcohol. In addition, diethyldithiocarbamate selectively inhibited p-nitrophenol hydroxylase in 2-h cultures from untreated and isoniazid-treated rats, as well as abolishing toxicity of the dichloropropanols. In 24-h cultures from isoniazid-treated rats diethyldithiocarbamate inhibited high affinity MCOD activity by 55% and there was also a small but significant inhibition of precocene II toxicity. These results indicate that isoniazid-inducible P4502E1 can mediate the toxicity of dichloropropanol.