Comparison of the Sensitivity of Hematopoietic Colony-Forming Cells in Different Proliferative States to Vinblastine2

Abstract

The survival of normal hematopoietic colony-forming cells in different proliferative states after exposure to vinblastine in vivowas measured and compared. Rapidly proliferating, exponential phase cells, and slowly proliferating, transitional phase cells were obtained from the femoral marrows of mice irradiated and then subsequently given 5 × 10⁶ normal bone marrow cells. Exponential phase colony-forming cells were much more sensitive to the action of the drug than were either normal or transitional phase cells. This was true both when the survival was measured as a function of dose for a 24-hour exposure and when it was measured as a function of time for a constant large dose of the drug. The results support the suggestion that the difference between the sensitivity of normal hematopoietic and rapidly proliferating lymphoma colony-forming cells to vinblastine can in part at least be explained on the basis of differences between their proliferative states.