Relationship of factor-induced proliferation to respiratory status in marrow progenitor cells

We have examined the respiratory status of murine and human marrow progenitor cells proliferating in response to growth factors. Proliferation of fresh marrow cells, which are almost entirely entering terminal differentiation, depends on oxidative phosphorylation as determined by oxygen uptake, lactic acid production, and effect of mitochondrial poisons which within minutes completely prevent incorporation of thymidine. However, marrow progenitors responding to growth factors in in vitro assays can proliferate in the presence of high concentrations of mitochondrial poisons, with mixed granulocyte/macrophage colonies being almost refractory to inhibition. We suggest that marrow anaerobiosis may have a physiological significance and may be of relevance to the aberrant respiration of leukemic cells which are considered to be derived from progenitor populations.