Hepatic artery administration of degradable starch microspheres. I. Effect on energy charge and incorporation of precursors into rat liver nucleic acids.

The effects of hepatic artery administration of degradable starch microspheres on liver energy charge and nucleic acid anabolism were studied in rats. Liver energy charge was evaluated 20 and 60 min after the injection of degradable starch microspheres. As compared to controls the microspheres had no effect on liver energy charge. The incorporation of orotic acid, uracil, and thymidine into liver RNA or DNA was studied 1 h after hepatic artery injection of precursor alone or together with degradable starch microspheres. Orotic acid and uracil incorporation into RNA was studied in normal rats and the DNA incorporation of thymidine in animals with regenerating livers. Orotic acid and thymidine were given in trace amounts. Uracil was given in amounts corresponding to a therapeutic dose of 5-fluorouracil. The addition of microspheres had no effects on the incorporation of the nucleic acid precursors into RNA or DNA. Thus, in the normal liver degradable starch microspheres administered by the hepatic artery had no influence on liver energy charge or RNA anabolism in the liver. Also the microspheres had no negative effects on the DNA anabolism in proliferating liver cells.