Effects of subchronic manganese chloride exposure on tambaqui (Colossoma macropomum) tissues: oxidative stress and antioxidant defenses.

GABRIEL D; RIFFEL AP; FINAMOR IA; SACCOL EM; OURIQUE GM; GOULART LO; KOCHHANN D; CUNHA MA; GARCIA LO; PAVANATO MA; VAL AL; BALDISSEROTTO B; LLESUY SF

ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY

SPRINGER

Lugar: Berlin; Año: 2013 vol. 64 p. 659 - 667

0090-4341

This study aimed to evaluate oxidative stress parameters in juvenile tambaqui (Colossoma macropomum) exposed to 3.88 mg l(-1) Mn(2+) 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 Mn(2+) in the water corresponded to increased levels of Mn(2+) 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 Mn(2+). 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.