Alterations of nuclear size profiles in AKR/J mice with spontaneous or transplanted leukemia

Electronic sizing with a Coulter Counter was used to measure the frequency and number of cells with a large nuclear volume in tissues from AKR/J mice with spontaneous, long passaged, or first passage leukemia. The mean percentage of cells with a large nuclear volume was 1% in the blood, 4% in the spleen, 10% in the bone marrow, and 5% in the thymus of nonleukemic AKR/J mice. The percentage of cells with a large nucleus increased to 14–83% in all four tissues from AKR/J mice with spontaneous leukemia. In mice with a long passaged leukemia, a progressive increase in the percentage of cells with a large nucleus in the spleen and blood was associated with an increase in the number of cells/tissue with a large nucleus. However, in the bone marrow, an increase in percentage of cells with a large nuclear volume appeared to be the result of a decrease in the number of cells/humerus with a small nuclear volume. In the thymus, there was only a slight increase in the percentage of cells with a large nucleus. In mice with a first passage leukemia, there was a progressive increase, until death of the animals (21 ± 1.9 days), in thymus weight and in the percentage of cells with a large nucleus. Also, the number of cells with a large nucleus increased in the spleen and bone marrow until day 12. Thereafter, there was a decrease in the total number of cells and number of cells with a large nucleus.