KINETIC STUDIES ON METABOLISM OF ETHYLMORPHINE BY ISOLATED HEPATOCYTES FROM ADULT RATS

Hepatocytes of adult rats were isolated by infusion of a hyaluronidase collagenase mixture. High yields of cells excluding trypan blue were obtained. These cells, in Hank''s buffer containing rat serum and 0.1% glucose, N-demethylate [3H-CH3-N]ethylmorphine. The formaldehyde initially formed is further metabolized to tritiated H2O. Fifteen per cent of the original metabolic activity was observed after 21 h at 37.degree. in 5% CO2-air, and cumulative metabolism is linear for up to 90 min under these conditions. The Km for the N-demethylation of [3H-CH3-N]ethylmorphine is 50 .mu.M, 20% of the value observed for this reaction by microsomal preparations. An active transport of the substrate into the cell is postulated to account for this difference.