[Effect of treatments of different modalities on the nucleoside phosphate kinase activity of normal and neoplastic cells].

The activity of nucleoside phosphate kinases was studied in experimental transplantable tumours under chemotherapy, in the liver of normal rats treated with hepatocarcinogens, or in human lung tumours after irradiation. The above factors have been found to increase the activity of uridine phosphate kinase, reducing at the same time the activity of thymidine phosphate kinase. The data suggest the existence of an unknown regulatory mechanism responsible for the normal levels of uridylates and thymidylates, thymidine kinase and uridine kinase shunt.