Tissue Trace Element Change after Total Body Irradiation

Purpose: In this study, we examined the changes of tissue contents of trace elements and iron after total body irradiation (TBI) and their possible impact on late toxicities. Material and Methods: 20 female Wistar rats were randomly assigned to two groups – either radiation (n = 10) or control (n = 10). Rats in the radiation group received TBI of 5 Gy in a single fraction. Rats were sacrificed and tissue samples of heart, lung and kidney were taken 8 weeks after radiation. Tissue levels of zinc, copper, magnesium, manganese and iron analysis were performed with an atomic absorption spectrophotometer and suprapure grade standard solutions. One kidney of each animal was taken for electron microscopic analysis. Blood samples were collected from all animals and the blood chemistry related to kidney function was studied. Results: The kidney levels of Fe and Cu significantly increased 8 weeks after irradiation (p < 0.05). The Cu/Zn ratio did not reach statistical significance in any tissue, however in kidney, there was a tendency to rise (p = 0.08). Myocardium and lung content of trace elements and iron did not show any significant change 8 weeks after irradiation. Electron microscopic analysis showed significant injury in glomerular endothelial cells, renal tubules and thickening of basement membrane. Blood chemistry showed a significant rise in serum creatinine (p = 0.008) and calcium (p = 0.01) in the TBI group. Serum creatinine levels were 0.73 and 0.84 mg/dl, and serum calcium levels were 10.1 and 11.3 mg/dl in control and TBI groups, respectively. Conclusion: A sublethal dose of TBI causes deposition of Cu and Fe within the kidney after TBI. Deposition of these elements may have some additional role on the toxicity caused by direct radiation on the kidney.