Quantitative analysis of friend's disease in two inbred strains of mice with emphasis on bone marrow response.

Summary The anatomical expression of a murine viral leukemia depends on variables of the host as well as of the virus (20). After inoculating two inbred strains of mice with Friend9s virus, we compared numerical changes of the marrow cells, peripheral leukocytes, and organ weights at predetermined intervals. Friend9s disease engenders measurable changes in the bone marrow that disclose significant differences between the two inbred strains. Although most stem cells of both strains proliferate, they proliferate at different rates. The erythroblasts show a qualitatively different response. Correlation between organ weights, marrow cell counts, and the time at which the peripheral blood becomes leukemic suggests that the leukemic blood cells in Friend9s disease are released by the spleen, despite conspicuous alterations of the bone marrow. The experiments show that the progress of the leukemic process can be measured as a function of controllable host factors.