Trivalent chromium induces oxidative stress in goldfish brain

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• 作者：Oleh V. Lushchak ; Olha I. Kubrak ; Ihor M. Torous ; Tetyana Yu. Nazarchuk ; Kenneth B. Storey ; Volodymyr I. Lushchak
• 关键词：Oxidative stress ; Antioxidant enzymes ; Glutathione ; Lipid peroxides ; Protein carbonyls
• 刊名：Chemosphere
• 出版年：2009
• 出版时间：March 2009
• 年：2009
• 卷：75
• 期：1
• 页码：56-62
• 全文大小：487 K

文摘

Although information on the effects of Cr⁶⁺ in biological systems is abundant, Cr³⁺ has received less attention. Toxic effects of chromium compounds are partially associated with activation of redox processes. Recently we found that Cr⁶⁺ induced oxidative stress in goldfish tissues and the glutathione system was shown to play a protective role. The present study aimed to investigate free radical processes in brain of goldfish exposed to CrCl₃. Trivalent chromium at a concentration of 50 mg L⁻¹ was lethal and therefore we chose to examine sublethal dosages of 1.0–10.0 mg L⁻¹ in aquarium water. The levels of lipid peroxides and protein carbonyls (measures of oxidative damage to lipids and proteins) in brain increased after 96 h exposure of goldfish to Cr³⁺. However, exposure to 1.0–10.0 mg L⁻¹ Cr³⁺ decreased total glutathione concentration in brain by 50–60 % . Oxidized glutathione levels also fell by 40–60 % except at the 10.0 mg L⁻¹ dosage where they decreased by 85 % . Therefore, 10.0 mg L⁻¹ Cr³⁺ significantly reduced the ratio [GSSG]/[totalGSH] to 35 % of the control value. Chromium treatment did not affect the activity of superoxide dismutase, but reduced the activities of catalase by 55–62 % and glutathione-S-transferase by 14–21 % . The activities of glucose-6-phosphate dehydrogenase and glutathione reductase were unchanged under any experimental conditions used. Therefore, it can be concluded that although Cr³⁺ exposure induced oxidative stress in goldfish brain, it failed to enhance the efficiency of the antioxidant system in the organ.