The series-compartment model for hepatic elimination.

An empirical model is presented for hepatic elimination of substrates which treats the liver as a series of compartments. The number of compartments serves as an adjustable parameter and determines the effect of changes in blood flow on elimination. By allowing variable dependence of clearance on blood flow, the model serves as a bridge between the extreme cases of venous equilibrium (the "well-stirred" model) and the "parallel-tube" model. The adjustable parameter in the model can be determined by measuring the clearance at different rates of blood flow, or at different extents of binding of the substrate to blood components. Examples are given for steady state elimination of several different substrates with linear and nonlinear elimination kinetics.