title: Early biochemical biomarkers for zinc in silver catfish (Rhamdia quelen) after acute exposure.
abstract: Contamination of aquatic ecosystems by metals causes various biochemical changes in aquatic organisms, and fish are recognized as indicators of environmental quality. Silver catfish were exposed to six concentrations of zinc (Zn): 1.0, 2.5, 5.0, 7.5, 10.0 and 12.5 mg/L for 96 h to determine the mean lethal concentration (LC50). The value obtained was 8.07 mg/L. In a second experiment, fish were exposed to concentrations of 1.0 or 5.0 mg/L Zn and a control for 96 h. Afterward, the tissues were collected for biochemical analysis. Lipid peroxidation, as indicated by thiobarbituric acid-reactive substance (TBARS), decreased in the liver and brain for all Zn concentrations tested, while in the gills TBARS levels increased at 1.0 mg/L and declined at 5.0 mg/L. Zn increased protein carbonyls in the muscle of silver catfish and decreased it in the other tissues. The enzyme superoxide dismutase increased in both exposed groups. However, catalase did not change. Glutathione S-transferase decreased in the liver and increased in the gills (1.0 mg/L), muscle (5.0 mg/L) and brain (1.0 and 5.0 mg/L). Nonprotein thiols changed only in brain and muscle tissue. Zn exposure inhibited acetylcholinesterase (AChE) activity in the brain at both concentrations tested, but did not change it in muscle. Exposure to Zn inhibited the activity of Na(+)/K(+)-ATPase in the gills and intestine at both concentrations tested. Our results demonstrate that Zn alters biochemical parameters in silver catfish and that some parameters such as AChE and Na(+)/K(+)-ATPase could be considered as early biomarkers of waterborne Zn toxicity.
authors.affiliation: Laboratório de Bioquímica Adaptativa e Toxicologia Aquática, Programa de Pós-Graduação em Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, RS, 97105.900, Brazil.
authors.forename: Jossiele
authors.initials: J
authors.lastname: Leitemperger
authors.affiliation: Laboratório de Bioquímica Adaptativa e Toxicologia Aquática, Programa de Pós-Graduação em Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, RS, 97105.900, Brazil.
authors.forename: Charlene
authors.initials: C
authors.lastname: Menezes
authors.affiliation: Laboratório de Bioquímica Adaptativa e Toxicologia Aquática, Programa de Pós-Graduação em Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, RS, 97105.900, Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Santi
authors.affiliation: Laboratório de Bioquímica Adaptativa e Toxicologia Aquática, Programa de Pós-Graduação em Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, RS, 97105.900, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Murussi
authors.affiliation: Laboratório de Bioquímica Adaptativa e Toxicologia Aquática, Programa de Pós-Graduação em Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, RS, 97105.900, Brazil.
authors.forename: Thais
authors.initials: T
authors.lastname: Lópes
authors.affiliation: Laboratório de Bioquímica Adaptativa e Toxicologia Aquática, Programa de Pós-Graduação em Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, RS, 97105.900, Brazil.
authors.forename: Maiara
authors.initials: M
authors.lastname: Costa
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal de Rio Grande (FURG), Rio Grande, RS, Brazil.
authors.forename: Lygia Sega
authors.initials: LS
authors.lastname: Nogueira
authors.affiliation: Laboratório de Bioquímica Adaptativa e Toxicologia Aquática, Programa de Pós-Graduação em Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Santa Maria, Santa Maria, RS, 97105.900, Brazil. vania.loro@gmail.com.
authors.forename: Vania Lucia
authors.initials: VL
authors.lastname: Loro
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002397:Catfishes / Q000378:metabolism*; D005260:Female; D029941:Fish Proteins / Q000378:metabolism; D005880:Gills / Q000187:drug effects / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007928:Lethal Dose 50; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015032:Zinc / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D029941:Fish Proteins; D013438:Sulfhydryl Compounds; D017392:Thiobarbituric Acid Reactive Substances; D014874:Water Pollutants, Chemical; D002374:Catalase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D000110:Acetylcholinesterase; D000254:Sodium-Potassium-Exchanging ATPase; D015032:Zinc
keywords: Aquatic contamination; Fish; Metal; Na+/K+-ATPase