SUPPRESSION OF MURINE LEUKEMIAS BY L-ASPARAGINASE INCIDENCE OF SENSITIVITY AMONG LEUKEMIAS OF VARIOUS TYPES: COMPARATIVE INHIBITORY ACTIVITIES OF GUINEA PIG SERUM L-ASPARAGINASE AND ESCHERICHIA COLI L-ASPARAGINASE

摘要: A survey of 109 recently derived leukemias the mouse revealed that sensitivity to suppression by guinea pig serum is a common property transplanted certain classes. The sensitive included five arose spontaneously in mice strains with low incidence leukemia and 21 were induced X-radiation. Two GPS-sensitive not more than GPS-resistant range standard chemotherapeutic agents. effectiveness L-asparaginase EC-2 from Escherichia coli EARAD1 depends upon conditions assay. Whereas it inhibitory when administered as single dose at time inoculation considerably effective GPS used treatment established leukemia. Permanent cures 7-day generalized transplants can be effected administration 2000 or units EC-2. Immunological factors apparently do contribute cure treated survivors are fully susceptible rechallenge minimal numbers cells same Reinoculated progressively growing have been successfully retreated blood clearance injected into much rapid L-asparaginase. After intraperitoneal EC-1 L-asparaginase, which does leukemia-inhibitory activity, only very levels enzyme activity could detected serum. E. its availability virtually limitless source will make possible extend study inhibition other tumors species small rodents.