Pharmacokinetics of inulin in blood and central lymph in the rat.

Inulin was used as a model drug for the study of factors influencing the transport of drugs across the blood-lymph barrier. The model drug was administered iv (0.75, 7.5 and 37.5 mg/kg) as a bolus and by infusion. Kinetic parameters in blood and central lymph including lymphatic bioavailability (FL) were determined. It has been found that FL is influenced (increased) by larger doses of inulin (FL extent 0.934 +/- 0.250 - 1.914 +/- 0.250), infusion concentration ratio lymph/blood in steady state was 0.941 +/- 0.013. Identical kinetic parameters were found in rats with differentiated content of total lipids in lymph (in fed and fasted group, FL were 0.861 +/- 0.167 and 0.934 +/- 0.250 respectively).