Background. Trace elements - zinc, copper and selenium are part of antioxidant enzymes, superoxide dismutase
(SOD) and glutathione peroxidase (GHPx). In renal diseases changes in the trace element metabolism may influence
the equilibrium in the antioxidant defence system and enhance the toxic effect of reactive oxygen molecules.
Methods and Results. The authors examined in 53 children with chronic neprophathies (34 with chronic
glomerulonephritis, 11 with chronic renal failure and 8 children included in a chronic dialyzation programme) zinc
and selenium in blood and urine and antioxidant enzymes SOD and GHPx in red blood cells. The lowest SOD activity
(737 ± 219 U/g Hb, p < 0.01) and serum zinc concentration (12.9 ± 3.2, p < 0.05) were found in children in the
terminal stage of uraemia, GHPx was as compared with the group of healthy children elevated in all groups of sick
children. In dialysed children GHPx was highest (p < 0.01) and correlated with urinary selenium concentrations
(r = -0.86, p < 0.05). The SOD activity depended on the serum copper concentrations (r = 0.78, p < 0.05). The highest
renal zinc and selenium excretion was recorded in patients with glomerulonephritis (p < 0.05).
Conclusions. The results support the hypothesis on a causal relationship between trace elements and antioxidant
SOD, GHPx, zinc, selenium, kidneys, chronic renal failure.