title: Hypoxia acclimation and subsequent reoxygenation partially prevent Mn-induced damage in silver catfish.
abstract: This study investigated if hypoxia acclimation modifies the hematological and oxidative profiles in tissues of Mn-exposed silver catfish (Rhamdia quelen), and if such modifications persist upon subsequent reoxygenation. Silver catfish acclimated to hypoxia (~3mgL-1) for 10days and subsequently exposed to Mn (~8.1mgL-1) for additional 10days exhibited lower Mn accumulation in plasma, liver and kidney, even after reoxygenation, as compared to normoxia-acclimated fish. Hypoxia acclimation increased per se red blood cells count and hematocrit, suggesting adaptations under hypoxia, while the reoxygenation process was also related to increased hematocrit and hemoglobin per se. Fish exposed to Mn under normoxia for 20days showed decreased red blood cells count and hematocrit, while reoxygenation subsequent to hypoxia increased red blood cells count. Hypoxia acclimation also prevented Mn-induced oxidative damage, observed by increased reactive species generation and higher protein carbonyl levels in both liver and kidney under normoxia. Mn-exposed fish under hypoxia and after reoxygenation showed decreased plasma transaminases in relation to the normoxia group. Moreover, acclimation to hypoxia increased reduced glutathione levels, catalase activity and Na+/K+-ATPase activity in liver and kidney during Mn exposure, remaining increased even after reoxygenation. These findings show that previous acclimation to hypoxia generates physiological adjustments, which drive coordinated responses that ameliorate the antioxidant status even after reoxygenation. Such responses represent a physiological regulation of this teleost fish against oxygen restriction and/or Mn toxicity in order to preserve the stability of a particular tissue or system.
authors.affiliation: Programa de Pós Graduação em Farmacologia, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil.
authors.forename: G S
authors.initials: GS
authors.lastname: Dolci
authors.affiliation: Departamento de Fisiologia e Farmacologia, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil.
authors.forename: H Z
authors.initials: HZ
authors.lastname: Rosa
authors.affiliation: Programa de Pós Graduação em Farmacologia, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil.
authors.forename: R C S
authors.initials: RC
authors.lastname: Barcelos
authors.affiliation: Programa de Pós Graduação em Bioquímica Toxicológica, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil.
authors.forename: L T
authors.initials: LT
authors.lastname: Vey
authors.affiliation: Programa de Pós Graduação em Farmacologia, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Santos
authors.affiliation: Programa de Pós-graduação em Química, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil.
authors.forename: P
authors.initials: P
authors.lastname: DallaVechia
authors.affiliation: Programa de Pós-graduação em Química, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil.
authors.forename: C
authors.initials: C
authors.lastname: Bizzi
authors.affiliation: Programa de Pós Graduação em Farmacologia, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil; Departamento de Fisiologia e Farmacologia, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Cunha
authors.affiliation: Programa de Pós Graduação em Farmacologia, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil; Departamento de Fisiologia e Farmacologia, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil.
authors.forename: B
authors.initials: B
authors.lastname: Baldisserotto
authors.affiliation: Programa de Pós Graduação em Farmacologia, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil; Departamento de Fisiologia e Farmacologia, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil; Programa de Pós Graduação em Bioquímica Toxicológica, UFSM, Universidade Federal de Santa Maria (UFSM), Av. Roraima n° 1000, Cidade Universitária, Camobi, Santa Maria 97105-900, RS, Brazil. Electronic address: marilise.burger@ufsm.br.
authors.forename: M E
authors.initials: ME
authors.lastname: Burger
mesh_terms: D000064:Acclimatization; D000818:Animals; D015415:Biomarkers / Q000097:blood; D002374:Catalase / Q000378:metabolism; D002397:Catfishes / Q000097:blood / Q000378:metabolism*; D019610:Cytoprotection; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D029941:Fish Proteins / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D000860:Hypoxia / Q000378:metabolism*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D017895:Manganese Compounds; D018384:Oxidative Stress / Q000187:drug effects; D050050:Protein Carbonylation / Q000187:drug effects; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013431:Sulfates / Q000633:toxicity*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D029941:Fish Proteins; D006454:Hemoglobins; D017895:Manganese Compounds; D013431:Sulfates; D014874:Water Pollutants, Chemical; D002374:Catalase; D000254:Sodium-Potassium-Exchanging ATPase; D005978:Glutathione; C039798:manganese sulfate
keywords: Hematological profile; Mn toxicity; Moderate hypoxia; Plasma transaminases; Rhamdia quelen