文摘
This study aimed to evaluate oxidative stress parameters in juvenile tambaqui (Colossoma macropomum) exposed to 3.88?mg?l? Mn2+ for 96?hours. Biomarkers of oxidative stress, such as thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and glutathione-S-transferase (GST) activities, as well as content of reduced glutathione (GSH), were analyzed in gill, liver, brain, and kidney. The presence of Mn2+ in the water corresponded to increased levels of Mn2+ accumulation according to the following sequence: gill?>?kidney?>?brain?>?liver. There was a significant increase in TBARS levels (40?%) and SOD activity (80?%) in addition to a significant decrease in GSH content (41?%) in gills of fish exposed to waterborne Mn2+. In hepatic tissue of the exposed animals, TBARS levels decreased significantly (35?%), whereas SOD (82?%) and GST activities (51?%) as well as GSH content (43?%) increased significantly. In brain of exposed juvenile fish, only significant decreases in SOD (32?%) and CAT activities (65?%) were observed. Moreover, the kidney of exposed fish showed a significant increase in TBARS levels (53?%) and a significant decrease in SOD activity (41?%) compared with the control. Thus, the changes in biomarkers of oxidative stress were different in the tissues, showing a specific toxicity of this metal to each organ.