Cell Division/drug effects; Lymphoma/metabolism; Ribonucleosides/metabolism; Adenosine/pharmacology; Animals; Ascitic Fluid; Aza Compounds/pharmacology; Biological Transport; Bromodeoxyuridine/pharmacology; Carbon Isotopes; Cell-Free System/drug effects; Cells, Cultured/metabolism; Guanosine/pharmacology; Inosine/pharmacology; Male; Mercaptopurine/administration & dosage; Mercaptopurine/antagonists & inhibitors; Mercaptopurine/pharmacology; Methotrexate/antagonists & inhibitors; Methotrexate/pharmacology; Mice; Neoplasm Transplantation; Neoplasms, Experimental/metabolism; Pyrazoles/pharmacology; Pyrimidinones/pharmacology; Pyrroles/pharmacology; Ribonucleosides/administration & dosage; Ribonucleosides/antagonists & inhibitors; Ribonucleosides/pharmacology; Thymidine/metabolism; Thymidine/pharmacology; Time Factors; Transplantation, Homologous