5-Fluorouracil incorporation into RNA of a rat liver adenocarcinoma after hepatic artery injection together with degradable starch microspheres.

The effect of degradable starch microspheres (DSM) on the cellular incorporation of 5-fluorouracil (FUra) was studied in rats with solitary liver tumours. 3H-labelled FUra [0.78 mg (6000 nmol)/kg b.wt.] was injected with saline or mixed with DSM, into the hepatic artery. Labelling of the acid soluble fraction (ASF), RNA and DNA of tumour, liver, bone marrow and small intestine was measured 60 minutes after injection. The DSM had no significant effect on the incorporation of FUra into the ASF or RNA, neither in tumour nor liver tissue. Regarding the tumour/normal tissue ratios of specific radioactivities, there was with DSM a higher tumour/liver and a higher tumour/bone marrow ratio in the ASF, indicating an increased tumour drug exposure with DSM. However, this was not accompanied by any significant increase in drug anabolism.