Biotransformation of pentachlorophenol, aniline and biphenyl in isolated rainbow trout (Oncorhynchus mykiss) hepatocytes: comparison with in vivo metabolism

1. The biotransformation of pentachlorophenol (PCP), aniline and biphenyl i n rainbow trout (Oncorhynchus mykiss) isolated liver cells was investigated to examine if fish hepatocytes represent a suitable alternative to the in vivo approach for studying the biotransformation of chemicals. Each compoun d was incubated at two concentrations (10 and 60 mu M) for 2 h. For compari son, the metabolic profile of these xenobiotics was also studied in urine a nd bile of trout orally exposed to 1.8-4.0 mg/kg wet wt of each compound. 2. In vitro as in vivo, PCP glucuronide and to a lesser extent PCP sulphate were the metabolites formed by trout from PCP. 3. Aniline was mainly metabolized to acetanilide and to a lesser extent to 2-aminophenol by isolated hepatocytes, but neither hydroxylated acetanilide nor conjugates were found in vitro whereas they were present in bile and u rine of trout treated with this chemical. 4. Trout hepatocytes metabolized biphenyl to hydroxylated and dihydroxylate d products and the corresponding glucuronides. These results correlated wel l with the metabolic profile obtained from the bile of trout exposed to thi s pesticide. 5. It is concluded that although hepatocytes are well suited for several ty pes of biotransformation studies, the fact that this system may in some cas es produce a different metabolic pattern than in vivo should be considered when attempting to extrapolate in vitro to in vivo data.