02342naa a2200337 a 450000100080000000500110000800800410001902400360006010000190009624501930011526000090030852012910031765000250160865000190163365000110165265000180166365000090168165000260169065000100171665000240172665000090175065000120175965300180177170000220178970000250181170000150183670000190185170000190187070000180188977300970190719526782013-03-11       2012    bl uuuu     u00u1 u    #d7 a10.1016/j.cbpc.2012.07.0022DOI1 aSAMPAIO, F. G.  aAntioxidant defenses and biochemical changes in the neotropical fish pacu, Piaractus mesopotamicusbresponses to single and combined copper and hypercarbia exposure.h[electronic resource]  c2012  aThis study investigated the potentially detrimental effects of copper and elevated aquatic CO2 (hypercarbia), alone or in combination, on pacu, Piaractus mesopotamicus. Fish were exposed for 48 h to control (no copper 2+ ?1addition in normocarbia), to 400 ?g Cu L , to hypercarbic (1% CO2; PCO2 = 6.9 mm Hg) water and to 400 ?g Cu2+L?1 +hypercarbia. In liver the single factors caused an increase in lipid hydroperoxide concen- tration that was not observed when the factors were combined. Copper exposure elicited increased hepatic superoxide dismutase activity, irrespective of aquatic CO2 level. On the other hand, the effects of copper on hepatic glutathione peroxidase activity were dependent on water CO2 levels. The two stressors combined did not affect hepatic catalase activity. Hypercarbic water caused a decline in plasma glucose concentration, but this was not observed when hypercarbia was combined with copper exposure. Copper caused a decrease in branchial Na+/K+-ATPase activity that was independent of water CO2 level. Copper caused an increase in branchial metallothionein concentration that was independent of water CO2 level. Thus, branchial metallothionein and Na+/K+ -ATPase were effective biomarkers of copper exposure that were not af- fected by water CO2 level.  aAntioxidant activity  aCarbon dioxide  aCopper  aEcotoxicology  aFish  aResistance mechanisms  aCobre  aDióxido de carbono  aPacu  aToxidez  aAntioxidantes1 aBOIJINK, C. de L.1 aSANTOS, L. R. B. dos1 aOBA, E. T.1 aKALININ, A. L.1 aLUIZ, A. J. B.1 aRANTIN, F. T.  tComparative Biochemistry and Physiology, Part C, New Yorkgv. 156, n. 3-4, p. 178-186, 2012.