PROLONGED EXPRESSION OF BIOTRANSFORMATION ACTIVITIES OF RAT HEPATOCYTES COCULTURED WITH ESTABLISHED CELL-LINES

Co-culture of hepatocytes with fibroblastic cells (C3H/10T 1 2 and 3T3) allowed the expression of phase I and II biotransformation enzymes for a prolonged time in culture. After 7 days in co-culture, cytochrome P-450 and monooxygenase activities were still 20-30% of the initial value, while in pure hepatocyte cultures they were undetectable. NADPH-cytochrome c reductase and conjugation activities remained at nearly initial levels for at least 7 days in co-cultured hepatocytes. Finally, in co-cultures a clear and prolonged induction of monooxygenase activities by 3-methylcholanthrene and phenobarbital was observed. © 1990.