Conjugation of chemical carcinogens by primary cultures of human hepatocytes.

1. The conjugation of benzo[a]pyrene (BP) and 2-acetylaminofluorene (AAF) was investigated in primary cultures of human hepatocytes. Human hepatocytes conjugated 12.5-63% of the BP and 1.7-52% of the AAF to sulphates and glucuronides over a thousand-fold concentration range. 2. BP is conjugated to glucuronides from non-detectable levels to 50%, and to sulphates from non-detectable levels to 30%. The major conjugated metabolites are the highly polar metabolites. 3. AAF is conjugated to glucuronides from 1.5 to 51% and to sulphates from 0.2 to 12%. The C-hydroxylated AAF metabolites were conjugated to glucuronides more than N-hydroxy AAF and aminofluorene metabolites.