Comparison of Radiation Sensitivity, Endogenous Colony Formation, and Erythropoietin Response Following Prolonged Hypoxia Exposure

Abstract

Abstract : Experiments have been carried out to evaluate the effect of continual hypoxia exposure on the hematopoietic system of mice. Three parameters have been investigated: (A) mortality sensitivity to x irradiation at dose levels between 675 and 775R, (B) formation of endogenous erythroid colonies in the spleen after x irradiation, and (C) response to erythropoietin injection. The results indicate that sensitivity to x irradiation is lessened, colony formation is greater, and erythropoietin response is enhanced if irradiation is performed 3 days after cessation of hypoxia on mice previously exposed for 3 to 4 weeks to one-half atmosphere of air. The findings suggest that prolonged stimulation of the erythroid system results in an enlargement of those hematopoietic compartments associated with cellular reproduction and with response to erythropoietic stimulation. (Author)