Combined Effects of Total Body X-Irradiation and Radiant Energy Thermal Burns on the Osmotic and Mechanical Fragility of the Erythrocyte

Abstract

Osmotic and mechanical fragilities of rat erythrocytes were measured during the 30-day interval following severe and moderately severe burns, 100 and 500 r of whole body ionizing radiation, and combinations of the 2 traumata. Although it is difficult to demonstrate an increased fragility as early as 4 hours after severe burns, there is most probably an increased resistance to osmotic hemolysis 24 hours later as the result of removal of the most fragile cells. This is a transient finding and normal fragilities are found on the 3d day. During the recovery period an increased resistance to osmotic hemolysis develops which is discussed as a possible result of increased red cell turnover. Irradiation produces an increased osmotic resistance at the 500-r level but not at 100 r. This change is correlated with removal of fragile cells and increased red cell turnover. Combination of the traumata brings about essentially additive results insofar as osmotic fragility is concerned. Mechanical fragility was increased by lethal doses of ionizing radiation and by lethal combinations of ionizing radiation and burns when neither trauma was lethal alone. It is thought that the increased mechanical fragility may be a sign of impending death in irradiated animals either in the presence or absence of other complicating traumata.