[Interrelationship between activity of nuclear ribonucleotide reductase and DNA synthesis of hepatocyte nuclei during liver tissue regeneration]. / Vzaimosviaz' aktivnosti iadernoi ribonukleotidreduktazy s sintezom DNK v iadrakh gepatotsitov pri regeneratsii pecheni.

Dynamics of 3H-thymidine incorporation into nuclear DNA and activity of nuclear ribonucleotide reductase were studied within 2 days after partial hepatectomy. The curves describing dynamics of DNA synthesis and the activity of ribonucleotide reductase were of wave-shaped pattern. Maximal enzymatic activity was reached 2 hrs before the nuclear DNA synthesis maximum. An inhibitor of ribonucleotide reductase was found in the globulin fraction of intact liver nuclei; after addition of the inhibitor the activity of the enzyme was decreased 4-5-fold, if the ratio of protein in preparations inhibitor/enzyme was as high as 1:40.

[Thymidine kinase and nucleoside phosphotransferase in blood of animals after partial hepatectomy and in patients with inflammatory diseases]. / Timidinkinaza i nukleozidfosfotransferaza v syvorotke krovi zhivotnykh posle chastichnoi gepatéktomii i u liudei s vospalitel'nymi zabolevaniiami.

Distinct activation of thymidine kinase (exceeding 2-3-fold the control values) as well as of nucleoside phosphotransferase (about 50% higher as compared with controls) was observed in blood serum of rats within 24 hrs after partial hepatectomy. Within 48 hrs after beginning of the tissue regeneration the activities of both these enzymes were decreased 1.5-fold; the values normalized within 72 hrs. These enzymatic activities were detected in blood of the patients with impairments of liver, kidney and some other tissues.

[Effect of sturines A and B on DNA synthesis and ribonucleotide reductase and thymidine kinase activity in regenerating rat liver]. / Vliianie sturinov A i B na sintez DNK i aktivnost' ribonukleotidreduktazy i timidinkinazy v regeneriruiushchei pecheni krys.

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.