Transplantable granulocytic leukemia in strain 13 guinea pigs

The occurrence of a granulocytic leukemia in 1 of 40 female strain 13/N guinea pigs given N-nitroso-N-butylurea continuously in their drinking water for 21 weeks is reported here. This leukemia has been successfully transplanted in this guinea pig strain for 13 transplant generations by i.p. inoculation of leukemic blood or marrow cells. Macroscopically and microscopically, this leukemia resembles the chronic myelogenous form in humans. Histochemical studies showed, however, that unlike the human leukemic cells those in the leukemic guinea pigs are alkaline phosphatase positive. Electron microscopic studies of the guinea pig leukemic cells revealed the presence of numerous intracisternal A-type particles that are not found in corresponding normal leukocytes.