Effects of cytosine arabinoside on the incorporation of pyrimidine nucleosides into hamster cells transformed by herpes simplex type 1 and type 2 viruses and by human cytomegalovirus

The incorporation of ³H-thymidine and ³H-deoxycytidine into acidoprecipitable fraction of hamster cells transformed by herpes simplex viruses type 1 and type 2 and of ³H-thymidine into hamster cells transformed by human cytomegalovirus was found to be resistant to the action of cytosine arabinoside. More ³H-thymidine was incorporated into these cells in the presence than in the absence of the drug. Similar stimulation of ³H-thymidine uptake could be achieved by using unlabelled deoxycytidine instead of cytosine arabinoside. Incorporation of both nucleosides into spontaneously and SV40 transformed cells was efficiently inhibited by the drug.