Influence of whole-body gamma-irradiation upon rat erythrocyte: lipid peroxidation and osmotic fragility.

The effects of whole-body gamma-irradiation of rats (8 Gy) on erythrocyte enzymes and biochemical components involved in lipid peroxidation were studied. Decreased superoxide dismutase and glutathione reductase activities, and lowered concentrations of reduced glutathione, were found to be the main factors responsible for the observed increase in lipid peroxidation in the erythrocytes of irradiated rats. This increased lipid peroxidation did not result in a greater tendency to hemolysis in hypotonic media; on the contrary, the mean osmotic fragility was decreased at days D + 1 and D + 3 after irradiation. The behavior of the erythrocyte populations towards hemolysis in hypotonic media appeared to be most homogeneous at days D + 4 and D + 8 after irradiation, which correspond to maxima of malonic dialdehyde concentrations in erythrocytes. Such a synchrony of variations suggests that crosslinking of primary amino groups of proteins or phospholipids by malonic dialdehyde might produce a rigidification in erythrocyte membranes, possibly leading to a more homogeneous behavior of the erythrocyte populations towards hemolysis in hypotonic media.