Use of the Rainbow Trout Hepatoma Cell Line, RTH-149, in a Cytotoxicity Assay

Abstract

The rainbow trout hepatoma cell line, RTH-149, was evaluated for use as a bioindicator cell type in the neutral red cytotoxicity assay. The cells were exposed for six days to various polycyclic aromatic hydrocarbons, including chemicals that are direct-acting toxicants and chemicals that require enzymatic biotransformation to cytotoxic metabolites. Whereas benzo[a]pyrene was only slightly cytotoxic, its metabolites — (±)trans-7,8-diol-benzo[a]pyrene and 3-hydroxy-benzo[a]pyrene — were highly cytotoxic. 7,12-Dimethylbenz[a]anthracene was cytotoxic, but cytotoxicity did not occur with benzo[a]anthracene, benzo[b]fluoranthene and benzo[k]fluoranthene. This cell line appears to lack sufficient xenobiotic metabolising capacity to biotransform many of these polycyclic aromatic hydrocarbons to activated cytotoxic metabolites.