Studies on Thymidine Kinase, Thymidylate Kinase, and Deoxycytidylate Deaminase of Chang Liver Cells

Studies on thymidine kinase, thymidylate kinase, and deoxycytidylate deaminase of Chang liver cells.

The activity levels of thymidylate kinase and deoxycytidylate deaminase in Chang human liver cells in tissue culture were measured during a normal S-day growth cycle. The activity of both enzymes showed considerable variations during different phases of growth, being high in rapidly proliferating and low in nonproliferating cultures. Data are presented which indicate that deoxycytidylate deamin...

Studies on Normal and Leukemic Leukocytes. Vi. Thymidylate Synthetase and Deoxycytidylate Deaminase.

Nucleotide interconversions. IV. Activities of deoxycytidylate deaminase and thymidylate synthetase in normal rat liver and hepatomas.

Normal and neoplastic rat liver was analyzed for deoxycytidylate deaminase and thymidylate synthetase. For these assays, highly sensitive radiochemical methods capable of detecting the formation of less than 0.001 /~mole of deoxyuridylate and thymidylate were employed. Deoxycytidylate deaminase was found in normal adult rat liver, rat embryo liver, regenerating liver, Novikoff hepatoma, Dunning...

Hormonal effects on thymidine kinase and thymidylate kinase activity of estrogen-dependent tumors in the rat.

In estrogen-induced, estrogen-dependent, mammary and adrenocorlical carcinomas, the specific activities of t lie tliymidine kinasc and thymidylate kinase decreased significantly within 2 to 4 days after removal of the source of estrogen of the host. After 7 days, these changes were even more marked in the adrenal tumors. Similar changes were not observed in the activity of these enzymes in auto...

Thymidine kinase, thymidylate synthase, and endothelial cell growth under hyperoxia.

To determine the respective role of thymidine kinase and thymidylate synthase activities in the hyperoxia-induced decrease in DNA synthesis and their relationship with cell replication, we measured these two enzyme activities in primary cultures of porcine aortic endothelial cells under different O2 concentrations for various durations. In confluent cells, exposure to 95% O2 for 5 days reduced ...