title: Imazapyr+imazapic herbicide determines acute toxicity in silver catfish Rhamdia quelen.
abstract: Imazapyr (IMY) and imazapic (IMI) are imidazolinone herbicides which have been associated in a commercial formulation (Kifix(®)). To date, there are no studies on the toxicity of an IMY+IMI herbicide in fish. This work aimed to assess the acute toxicity (24 and 96 h) of IMY+IMI (0, 0.488 and 4.88 µg/L) towards Rhamdia quelen through hematological, biochemical, immunological, ionoregulatory and enzymatic indexes. Red blood cell count was lower at 4.88 than at 0.488 µg/L (24 and 96 h); mean corpuscular volume was lower than control at both concentrations (24 h) and at 0.488 µg/L (96 h); lymphocytes declined at 4.88 µg/L comparing to control (96 h); and monocytes increased at 4.88 µg/L (96 h) in comparison with the respective control and with 4.88 µg/L at 24h. Aspartate aminotransferase was higher at 0.488 µg/L (96 h) than the respective control and the respective concentration at 24 h; uric acid reduced at 4.88 µg/L comparing with 0.488 µg/L (96 h); and cortisol was lower at 4.88 µg/L compared to 0.488 µg/L and control (96 h). Herbicide exposure lowered plasma bactericidal activity at both concentrations (24 h) and at 0.488 µg/L (96 h); and plasma complement activity declined at 4.88 µg/L comparing with 0.488 µg/L and control (96 h), and was lower at all concentrations at 96 h than at 24 h. Plasma K(+) levels were higher at 4.88µg/L than in the remaining groups (24 and 96h); and Na(+) levels decreased at 4.88 µg/L compared to control (96 h). Na(+)/K(+)-ATPase and H(+)-ATPase activities in gills were lower at 4.88 µg/L comparing with control (24 h) and with the respective concentration at 96 h; and AChE activity in brain was higher at 0.488 and 4.88 µg/L than control (24 h) and the respective concentrations at 96 h, while in muscle it was higher at 0.488 and 4.88 µg/L than control (96 h) and the respective concentrations at 24 h. The present findings demonstrate that, despite IMY+IMI targets the animal-absent AHAS enzyme, such formulation displayed an acute toxic effect upon R. quelen homeostasis by impacting on vital functions such as immune defense, metabolism, ionoregulation and neurotransmission.
authors.affiliation: Department of Agricultural and Environmental Sciences, Federal University of Santa Maria (UFSM)/CESNORS, Linha 7 de Setembro, BR 386, Km 40, Frederico Westphalen, 98400-000 RS, Brazil. Electronic address: jgolombieski2012@gmail.com.
authors.forename: Jaqueline Ineu
authors.initials: JI
authors.lastname: Golombieski
authors.affiliation: Department of Physiology and Pharmacology, UFSM, Avenida Roraima 1000, Santa Maria (SM), 97105-900 RS, Brazil. Electronic address: sutilifj@gmail.com.
authors.forename: Fernando Jonas
authors.initials: FJ
authors.lastname: Sutili
authors.affiliation: Department of Physiology and Pharmacology, UFSM, Avenida Roraima 1000, Santa Maria (SM), 97105-900 RS, Brazil. Electronic address: josalbego2004@yahoo.com.br.
authors.forename: Joseânia
authors.initials: J
authors.lastname: Salbego
authors.affiliation: Department of Agricultural and Environmental Sciences, Federal University of Santa Maria (UFSM)/CESNORS, Linha 7 de Setembro, BR 386, Km 40, Frederico Westphalen, 98400-000 RS, Brazil. Electronic address: debyseben@hotmail.com.
authors.forename: Débora
authors.initials: D
authors.lastname: Seben
authors.affiliation: Department of Physiology and Pharmacology, UFSM, Avenida Roraima 1000, Santa Maria (SM), 97105-900 RS, Brazil. Electronic address: lutgressler@hotmail.com.
authors.forename: Luciane Tourem
authors.initials: LT
authors.lastname: Gressler
authors.affiliation: Department of Physiology and Pharmacology, UFSM, Avenida Roraima 1000, Santa Maria (SM), 97105-900 RS, Brazil. Electronic address: jessyka.arruda@hotmail.com.
authors.forename: Jéssyka Arruda
authors.initials: JA
authors.lastname: da Cunha
authors.affiliation: Department of Preventive Veterinary Medicine, UFSM, Avenida Roraima 1000, SM, 97105-900 RS, Brazil. Electronic address: letrevi@gmail.com.
authors.forename: Leticia Trevisan
authors.initials: LT
authors.lastname: Gressler
authors.affiliation: Department of Chemistry, UFSM, Avenida Roraima 1000, SM, 97105-900 RS, Brazil. Electronic address: larp_rz@yahoo.com.br.
authors.forename: Renato
authors.initials: R
authors.lastname: Zanella
authors.affiliation: Graduate Program in Nanoscience, Franciscan University, Rua dos Andradas 1614, SM, 97010-032 RS, Brazil. Electronic address: rodvaucher@hotmail.com.
authors.forename: Rodrigo de Almeida
authors.initials: Rde A
authors.lastname: Vaucher
authors.affiliation: Department of Plant Science, UFSM, Avenida Roraima 1000, SM, 97105-900 RS, Brazil. Electronic address: eniomarchesan@gmail.com.
authors.forename: Enio
authors.initials: E
authors.lastname: Marchesan
authors.affiliation: Department of Physiology and Pharmacology, UFSM, Avenida Roraima 1000, Santa Maria (SM), 97105-900 RS, Brazil. Electronic address: bbaldisserotto@hotmail.com.
authors.forename: Bernardo
authors.initials: B
authors.lastname: Baldisserotto
mesh_terms: D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D002397:Catfishes / Q000097:blood* / Q000276:immunology / Q000378:metabolism; D005880:Gills / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D006540:Herbicides / Q000032:analysis / Q000633:toxicity*; D007093:Imidazoles / Q000032:analysis / Q000633:toxicity*; D007113:Immunity, Innate / Q000187:drug effects*; D009132:Muscles / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D009525:Niacin / Q000031:analogs & derivatives* / Q000032:analysis / Q000633:toxicity; D009539:Nicotinic Acids / Q000032:analysis / Q000633:toxicity*; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood; D023382:Toxicity Tests, Acute; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
chemical_list: D001786:Blood Glucose; D006540:Herbicides; D007093:Imidazoles; D009539:Nicotinic Acids; D014874:Water Pollutants, Chemical; D009525:Niacin; C076656:imazapyr; D012964:Sodium; D001219:Aspartate Aminotransferases; C481028:imazapic; D011188:Potassium
keywords: AChE; ATPases; Blood cells; Cortisol; Natural immunity; Plasma ions