Abstract
Repetitive intravenous injections of a small dose of dibutylnitrosamine frequently induced acute leukemias of reticulumcell type in low-leukemic mice with an average latent period of 152 days and with an average effective dose of 244μg. Two cases of leukemias were transplantable in syngeneic hosts.
Electron microscopic study revealed no virus-like particles in the leukemic cells.
The modal number of chromosomes of transplanted leukemic cells shifted from 40 in earlier passages to 41 in later. Through those passages about 50 per cent of cells with 40 chromosomes and about 90 per cent of cells with 41 chromosomes had one chromosome characterized by a secondary constriction.
Discussion was made on some factors responsible for leukemogenesis by dibutylnitrosamine.
