Increased uptake of 5-FU in experimental liver tumours by simultaneous infusion of norepinephrine

The effect of the simultaneous administration of norepinephrine and 5-fluorouracil (5-FU) on the uptake of radiolabelled 5-FU by liver tumours was studied in rats. Three different concentrations of 5-FU were used (15, 1.5 and 0.15 microgram/g body weight). The drugs were infused over a 30 min period via the hepatic artery, following cannulation of the gastroduodenal artery. The radioactivity in liver tumour, normal liver, lungs and intestines was estimated by liquid scintillation counting. At all concentrations tested, an increased uptake of radioactive 5-FU was found in the tumour when norepinephrine was infused. Tumour/liver ratios also increased significantly in all these cases. No significant differences were noted between norepinephrine infused and control animals in the radioactivity in normal liver, lungs and intestines. The effects noted were possibly due to changes in blood flow within the liver, but the possibility of a direct effect of norepinephrine on DNA metabolism is discussed.