Growth pattern of a transplantable acute myeloid leukemia in the rat

A generalized acute myeloid leukemia was induced in inbred Sprague-Dawley rats by intravenous injection of chloroleukemia cells. In the bone marrow, colonization by blast cells was observed soon after transplantation and at the end of the disease leukemia cells accounted for about 70% of the whole cell population. In the peripheral blood, erythrocyte and platelet counts decreased late in the disease, while from day 5 onwards there was a progressive increase in the leukocyte count owing to blast cells released into the bloodstream. Spleen, liver and central nervous system were also involved in the disease. The survival time of transplanted animals correlated with the number of cells injected: after transplantation of 2 × 10⁷ chloroleukemia cells survival time was 8.3 days, and with each 10-fold reduction of the inoculum survival time increased by about 2.5 days. The data presented show that Shay chloroleukemia mimics some features of human acute myeloid leukemia and possesses a predictable and highly reproducible growth rate, thus providing a further useful experimental model.