The combined effect of copper and low pH on antioxidant defenses and biochemical parameters in neotropical fish pacu, Piaractus mesopotamicus (Holmberg, 1887)

Author(s)

Sampaio, Fernanda Garcia ^[1] ; Boijink, Cheila de Lima ^[2] ; Bichara dos Santos, Laila Romagueira ^[3] ; Oba, Eliane Tie ^[4] ; Kalinin, Ana Lucia ^{[5, 1]} ; Rantin, Francisco Tadeu ^{[5, 1]}

Affiliation

^[1] Univ Fed Sao Carlos, Lab Zoophysiol & Comparat Biochem, Dept Physiol Sci, BR-13565905 Sao Carlos, SP - Brazil

^[2] Brazilian Agr Res Corp EMBRAPA, Minist Agr, Manaus, Amazonas - Brazil

^[3] Univ Sao Paulo, Dept Physiol & Biophys, Inst Biomed Sci, Sao Paulo - Brazil

^[4] Brazilian Agr Res Corp EMBRAPA, Minist Agr, Macapa, AP - Brazil

^[5] Natl Inst Sci & Technol Comparat Physiol FAPESP C, Sao Paulo - Brazil

• Document type: Journal article
• Source: ECOTOXICOLOGY; v. 19, n. 5, p. 963-976, JUN 2010.
• Web of Science Citations: 10

Abstract

Copper sulfate is widely used in aquaculture. Exposure to this compound can be harmful to fish, resulting in oxidative metabolism alterations and gill tissue damage. Pacu, Piaractus mesopotamicus, (wt = 43.4 +/- A 3.35 g) were distributed in experimental tanks (n = 10; 180 l) and exposed for 48 h to control (without copper addition), 0.4Cu (0.4 mg l(-1)), 0CupH (without copper addition, pH = 5.0) and 0.4CupH (0.4 mg l(-1), pH = 5.0). In liver and red muscle, the superoxide dismutase (SOD) was responsive to the increases in the aquatic copper. The plasmatic intermediary metabolites and hematological variables in the fish of group 0.4Cu were similar to those of the control group. Conversely, the exposure to 0.4CupH caused an increase in the plasmatic lactate, number of red blood cells (RBC) and hemoglobin (Hb). Plasmatic copper concentration {[}Cu(p)] increased in group 0.4Cu and 0.4CupH, which is higher in group 0.4CupH, suggests an effect of water pH on the absorbed copper. Exposure to 0.4Cu and 0.4CupH resulted in a reduction in the Na(+)/K(+)-ATPase activity and an increase in metallothionein (MT) in the gills. Exposure to 0CupH caused a decrease in glucose and pyruvate concentrations and an increase in RBC, Hb, and the branchial Na(+)/K(+)-ATPase activity. These responses suggest that the fish triggered mechanisms to revert the blood acidosis, save energy and increase the oxygen uptake. MT was an effective biomarker, responding to copper in different pHs and dissolved oxygen. Combined-factors caused more significant disturbance in the biomarkers than single-factors. (AU)