Effect of hepatic artery ligation on the incorporation of 3H-orotic acid into an adenocarcinoma transplanted to rat liver.

In the model of secondary liver cancer in Wistar rats a study was made of the influence of hepatic artery ligation (HAL) on the amount of nucleotides and RNA in tumor and liver tissue and on the uptake of 3H-orotic acid into these compounds and DNA after labelling for 90 minutes. Ten days after inoculation with tumor cells into the central liver lobe, a catheter was placed into the portal vein in all rats and in half of them the hepatic artery was ligated. On days one, three, five or ten, rats were given 3H-orotic acid through the catheter. On day ten 3H-orotic acid was also infused via the femoral vein or intraperitoneally. After HAL there was a decrease in the nucleotide and RNA content of the tumor cells after one, three and five days. There was no such decrease in the liver cells. In all HAL rats there was an increase in the nucleotide and RNA content of the tumor cells at day ten compared to day five. The ratio of RNA to acid soluble fraction labelling in tumors was also increased on day ten in all groups compared to HAL rats at day five. The increased uptake of 3H-orotic acid into tumour RNA at day ten after HAL strongly suggests rearterialization. There was no support for an increased vascularization of the tumor from the portal vein on day three or five. In the liver tissue, HAL had no influence. This experimental study gives no support for the use of hepatic dearterialization followed by intraportal infusion av cytostatic agents in clinical settings.