Age-related increase in erythrocyte oxidant sensitivity.

Unlike erythrocytes from elderly humans, red blood cells from old mice are not more sensitive than are cells from young animals to lysis in hypotonic solutions, probably because the mean corpuscular volume decreases rather than increases with age in this species. However, when subjected to an oxidant stress (sodium ascorbate) red blood cells from old animals accumulate more methemoglobin and fewer remain intact than is the case with red blood cells from young mice. The data suggest that this increased vulnerability to oxidative damage is manifest relatively early in the lifespan of red blood cells from old animals and is not solely a property of the older cells. The pathogenesis of the decreased resistance to peroxidation is not known, but it does not appear to be the result of changes in reduced glutathione, NADH: methemoglobin reductase, superoxide dismutase, glutathione reductase, glutamic-oxaloacetic transaminase, or glucose 6-phosphodehydrogenase.