Effect of cytosine arabinoside triphosphate on deoxyribonucleic acid synthesis in permealysed cells from ehrlich ascites tumour: Studies of phosphorylated drug metabolites on quasi-normal deoxyribonucleic acid replication

Abstract

Cytosine arabinoside triphosphate (ara-CTP) is a strong inhibitor of DNA synthesis in permealysed Ehrlich ascites cells, and this effect is rapidly reversed by dCTP but not by d-cytidine. Cytosine arabinoside is a weak inhibitor of DNA synthesis in permealysed Ehrlich ascites cells, and this effect is reversed by both dCTP and d-cytidine. A slightly improved assay system is described, and the permealysed ascites cells are shown to slowly lose activity during assays although DNA polymerase activity is not lost. An explanation of the effect of ara-CTP on DNA synthesis in permealysed cells and other systems is presented.