Incorporation of pyrimidines and 5-fluoropyrimidines into normal tissues and an adenocarcinoma transplanted into the liver in rat.

In a model of secondary liver cancer in Wistar rats, the incorporation of tracer doses of pyrimidines and 5-fluoropyrimidines into the acid-soluble fraction, RNA and DNA of several normal tissues and of an experimental adenocarcinoma of the colon transplanted to the liver of rat was determined 90 min after infusion of the substances via the gastroduodenal artery. There was a higher incorporation after injection of FUra than after uracil into tumor RNA. There was very little labeling of DNA by FdUrd but a greater labeling of RNA following injection of this substance than following deoxyuridine in all tissues including tumor except in liver, where it was of the same magnitude. All fluoro compounds gave high labeling of the acid-soluble fraction of the kidney and liver. The experiments will be continued with therapeutic doses of the fluoro compounds.