FLOW DEPENDENCE OF METOPROLOL ELIMINATION IN ISOLATED-PERFUSED RAT-LIVER

The effect of blood flow rates on hepatic elimination of metoprolol (M et) was studied in a recirculating isolated perfused rat liver system with a constant infusion of Met into the reservoir. This design ensure s that, at a steady state, the elimination rate of Met is a constant, The results showed that at flow rates of 10, 20, and 30 ml.min(-1), th e concentrations of Met entering the liver (C-in) were 7.6, 5.0, and 3 .4 mu g.ml(-1) and the concentrations leaving the liver (C-out) were 1 .2, 2.0, and 2.7 mu g.ml(-1), while the logarithmic average concentrat ions in hepatocytes (($) over cap C) were 3.4, 3.2, and 3.0 mu g.ml(-1 ), respectively. It is concluded that the hepatic elimination of Met i s flow-dependent, which is in accordance with the 'parallel tube' mode l.