Oxidative Damage to Lipids and DNA Concurrent with Decrease of Antioxidants in Rat Testes After Acute Iron Intoxication

Abstract

The effect of acute iron overload was studied in rat testes 20 h after a single administration of iron-dextran (500 mg/kg body wt, ip). Total testes iron content was 6.1-fold higher in iron-treated rats compared to controls. The endogenous level of lipid peroxidation was evaluated as 2-thiobarbituric acid-reactive substances (TBARS). Testes iron concentration (0.12-2.67 μmol/g of tissue) was positively correlated (r = 0.86; P < 0.01) with testes TBARS (26.2-77.5 nmol/g tissue). Testes content of lipid-soluble antioxidants, α-tocopherol, ubiquinol-9, and ubiquinol-10, were inversely correlated with testes iron content. The steady-state level of 8-oxo-7,8-dihydro-2′-deoxyguanosine in testes DNA was 25% higher (P < 0.01) in iron-treated rats compared to controls (2.4 ± 0.2 oxo8dG/105dG). The content of protein carbonyl groups (1.45 ± 0.13 nmol/mg protein) and the activity of glutamine synthase (1.32 ± 0.07 units/mg protein) were similar for the iron-treated and control rats. Fe treatment did not affect superoxide dismutase, catalase, and glutathione peroxidase activities. The results indicate that acute iron overload causes iron accumulation in rat testes, which is associated with increased lipid and DNA oxidative damage and depletion of lipid-soluble antioxidants.