A comparison of the effect of cytotoxic agents on agar colony forming cells, spleen colony forming cells, and the erythrocytic repopulating ability of mouse bone marrow.

Abstract

AbstractThree assays for bone marrow progenitor cells have been used to determine the effect of single doses of two cytotoxic agents, cyclophosphamide and vinblastine. The assays employed were the agar colony forming and spleen colony forming assays and the crythroid repopulating ability.In normal mice, there was little difference between the response of the progenitor cells assayed by the three methods, following cyclophosphamide: and no detectable difference following vinblastine.Bone marrow from continuously irradiated mice and bone marrow regenerating seven days following transplantation was also studied: in both these situations the proliferation rate of the progenitor cells is increased. Cyclophosphamide was found to be only slightly proliferation dependent with each assay. However, vinblastine was strikingly proliferation dependent. In irradiated mice and also in regenerating marrow the agar colony forming cells were many times more sensitive to this agent than were the other progenitor cells.These results show that under some but not all circumstances the agar colony forming and spleen colony forming cells behave similarly in C57BL mice, but are not a single population of cells.