The effect of various cytotoxic agents on bone marrow progenitor cells as measured by diffusion chamber assays.

Two diffusion chamber assays, termed the 'Full" chamber technique and the 'Empty' chamber technique, have been used to determine the effect of various doses of cyclophosphamide, vinblastine and busulphan on the population of diffusion chamber progenitor cells (DCPC). The diffusion chamber dose-response curves were compared to the progenitor cell survivals estimated by the spleen colony technique. The in vitro agar colony assay was also performed on the busulphan-treated marrow. The diffusion chamber and spleen colony techniques estimated similar survivals after cyclophosphamide and vinblastine treatment. However, with busulphan, the chamber, spleen colony and agar colony methods estimated different survivals. The indication is that the diffusion chamber techniques assay the same population of cells as the spleen colony technique, and that busulphan alters the capacity of surviving DCPC to generate granulocytes and macrophages.