Effect of gamma irradiation on magnesium content in rat tissues.

Studies in the field of radiation chemistry have shown that the greatest damage induced by ionizing radiation appears as a consequence of uncontrolled production of free radicals in the living organism, which have their origin in oxidative stress induced by ionizing radiation. Ionizing radiation also has an influence on the content of bio-essential elements in mammalian tissues. Analysis of the concentration of magnesium (Mg) seven days after whole body irradiation with a single dose of 4.2 Gy of gamma rays from a 60Co source, showed a slight reduction in Mg content in the following analyzed tissues: front brain (cerebral hemispheres with underlying structures except pituitary gland and hypothalamus) and adrenal glands from irradiated animals as compared to the non-irradiated controls, this difference however being not statistically significant. No significant differences in the content of Mg were detected in the pituitary glands between the two groups of animals. In contrast, a significantly higher concentration of Mg seven days after irradiation was measured in the hind brain-containing cerebellum with lateral lobes and flocculi (p < 0.005), hypothalamus (p < 0.0001) and testes (p < 0.05) of irradiated animals, when compared to the non-irradiated controls. This accumulation of Mg, in particular tissues of the Central Nervous System (CNS) and endocrine glands regulated by the pituitary gland and hypothalamus, may indicate the differential role Mg++ ions have in keeping the homeostasis of certain tissues, those of the brain, adrenal glands and testes after exposure to ionizing radiation.