The pharmacokinetics of inulin and urea: a comparison of the dose eliminated from a compartmental model and that eliminated in urine

Abstract

Abstract The distribution kinetics of inulin and urea were studied in the male rat to test the validity of a proposed compartmental model. The plasma curves could be adequately described by a biexponential function. For inulin, analysis of the results gave valid parameters in terms of an open two compartment model. These parameters did not necessarily predict the amount eliminated from the central compartment but did so under constant clearance conditions after allowance for a time lag between filtration and appearance of the drug in the collecting vessel. A triexponential fit interpreted in terms of a three compartmental model described the urea data.