Oxidative stress parameters and histopathological lesions in the liver and kidneys of manganese intoxicated rats

The aim of the research was to verify the theory of the free radical interaction of manganese compounds by assessing the activity of the enzymes: catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) in an experimental rat model of exposure to Mn. Forty five male Buffalo rats were divided into: control, group I (MnCl2; 5 mg/kg b.w.) and groUp II (MnCl2; 7.5 mg/kg b.w.). The activity of the enzymes: CAT, GPx, GR and GST activity were determined in the supernatants of the kidneys and liver. The histopathological alterations were evaluated in tissue sections. In rats intoxicated with Mn (group I and II) the decreased CAT and GR activities was observed in the liver, with a significantly lower the all enzymes activities measured in the kidneys. The the lowest CAT, GPx, GR and GST activity were observed in the kidneys of group II rat. An examination of hepatic tissues revealed moderate (group I) and severe (group II) histopathological lesions, with a insignificant lesions oserved in the renal tissues. It has been shown that manganese intoxication has cytotoxic activity in the kidneys and liver, causing an decrease in antioxidant enzymes activity. The observed histopathological changes in the liver tissue suggest sensitivity to oxidative stress in this organ. In the kidneys, despite a significant weakening of the antioxidant defense, insignificant histopathological lesions were found, which suggests a different defense mechanism independent of the antioxidant enzymatic defense.