The effect of inducing agents on the metabolism of ethidium bromide by isolated rat hepatocytes

The metabolism of ethidium bromide by isolated rat hepatocytes is significa ntly enhanced by pre-treatment of animals with phenobarbitone (PB) and 3-me thylcholanthrene (3-MC). Pre-treatment with PB and 3-MC results in a 2.5- a nd 1.5-fold increase, respectively in the amount of the principal metabolit e, ethidium 8-N-glucuronide, compared with that formed by hepatocytes from untreated rats. The formation of ethidium 3-N-glucuronide is not enhanced b y pre-treatment with either PB or 3-MC. Two new metabolites, hydroxyethidiu m glucuronide and a transient unidentified species, have been detected by H PLC and are formed only by hepatocytes from animals pre-treated with 3-MC. (C) 1999 Elsevier Science ireland Ltd. All rights reserved.