title: Copper sulfate affects Nile tilapia (Oreochromis niloticus) cardiomyocytes structure and contractile function.
abstract: Copper sulfate (CuSO(4))is an inorganic chemical product worldwide used as an algaecide and a fungicide in aquaculture and agriculture and being discharged into freshwater environments where it can affect the freshwater fauna, especially fishes. The impact of copper on fish cardiac function was analyzed in two groups of Nile tilapias, Oreochromis niloticus (control group and group exposed to 1 mg l(-1) of CuSO(4) for 96 h). Structural and ultra-structural changes were studied and related to perturbations of the inotropic and chronotropic responses of ventricle strips. Fish of Cu exposed group did not show significant alterations in the medium diameter and in the percentage of collagen in the cardiac myocytes when evaluated through the light microscope. However, the ultrastructural analysis revealed cellular swelling followed by mitochondrial swelling. The myofibrils did not show significant variations among groups. Force contraction was significantly decreased, and rates of time to tension increase (contraction) and decrease (relaxation) were significantly augmented after copper exposure. The results suggest that the copper sulfate impairs the oxidative mitochondrial function and consequently alters the cardiac performance of this species.
authors.affiliation: Laboratory of Zoophysiology and Comparative Biochemistry, Department of Physiological Sciences, Center of Biological Sciences and Health, Federal University of São Carlos- UFSCar, Via Washington Luís km 235, São Carlos, SP 13.565-905, Brazil.
authors.forename: Kátia Cristina
authors.initials: KC
authors.lastname: de Andrade Waldemarin
authors.forename: Rosiane Nascimento
authors.initials: RN
authors.lastname: Alves
authors.forename: Marcelo Emílio
authors.initials: ME
authors.lastname: Beletti
authors.forename: Francisco Tadeu
authors.initials: FT
authors.lastname: Rantin
authors.forename: Ana Lúcia
authors.initials: AL
authors.lastname: Kalinin
mesh_terms: D000818:Animals; D023681:Cichlids / Q000502:physiology*; D003094:Collagen / Q000378:metabolism; D019327:Copper Sulfate / Q000633:toxicity*; D005260:Female; D006352:Heart Ventricles / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D007091:Image Processing, Computer-Assisted; D008297:Male; D046529:Microscopy, Electron, Transmission; D008929:Mitochondria, Heart / Q000187:drug effects / Q000648:ultrastructure; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D009210:Myofibrils / Q000187:drug effects / Q000648:ultrastructure; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D003094:Collagen; D019327:Copper Sulfate