The liver receives two blood supplies, the portal vein (PV) and hepatic artery (HA). The isolated perfused rat liver preparation (IPRL) is widely used to examine physiological factors affecting the hepatic disposition of compounds, but usually it is perfused via the PV only. In the development of a more physiological dual perfused system, we examined three surgical procedures for HA perfusion--cannulation through the gastroduodenal artery, the aorta, and the celiac artery--using 14C-urea as the reference marker. Similar efflux profiles for 14C-urea were obtained for all three procedures, with a clear difference between HA and PV administration; however, cannulation of blood vessels and isolation of the HA supply were the most reliable with the celiac artery cannulation, making it the preferred procedure.