[Effect of sturines A and B on DNA synthesis and ribonucleotide reductase and thymidine kinase activity in regenerating rat liver].

After a single intravenous administration of sturines A and B into rats subjected to partial hepatectomy, during the periods, corresponding to maximal synthesis of DNA, incorporation of 3H-thymidine into nuclear DNA was decreased by 20-30% and incorporation into mitochondrial DNA--by 40-50%, as compared with control. The treatment with sturines led to distinct decrease in activity of nuclear thymidine kinase and ribonucleotide reductase but did not affect the enzymatic activity in mitochondria. The sturine preparations (at concentrations 10(-6)--10(-3) M) inhibited the activity of these enzymes (of both nuclear and mitochondrial origin) in vitro.