Dose-dependency of Tl+ kinetics as studied in rabbits

The dose-dependency of Tl+ kinetics was studied in rabbits by intravenous injection first of a 201Tl+ tracer dose and 2 weeks later of a 5.5 mumol/kg dose. For either dose level, an open three compartment model was appropriate to describe the course of the plasma concentration curve. With the dosage increase a slight to moderate decrease in the distribution volumes (11.2 l/kg versus 9.7 l/kg) and in the plasma clearance (13 ml/min versus 9 ml/min) was found. Two days after injection of both the high and the low dose considerable amounts of Tl+ were found in the intestinal contents and only small amounts were found in the bile.