| Abstract: | The effect of phytohemagglutinin (PHA) on the growth and number of granulocytic colonies (GC) developing on agar from bone marrow and spleen cells of normal and erythroleukemic mice inoculated with Rauscher leukemogenic virus was studied. Equal number of marrow cells from erythroleukemic mice produced twice as many colonies as those from normal mice. The number of GC developing from either normal and leukemic spleen cells was only 20% to 25% of that arising from marrow cells. The number of cells within each colony was significantly larger in GC formed by myelogenous leukemic cells than those arising from normal cells even though they had similar morphologic features. The addition of 100 μg of PHA per 105 cells reduced the number of GC arising from normal and leukemic cells by 35% and 50%, respectively. Treatment with periodate which mainly inhibits its mitogenic activity, abolished the inhibitory effects of PHA on proliferation of granulocytic cells. |
