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Campo DC | Valor | Idioma |
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dc.contributor.author | Matsuo, Aline Y.O. | - |
dc.contributor.author | Playle, Richard C. | - |
dc.contributor.author | Val, Adalberto Luis | - |
dc.contributor.author | Wood, Chris M. | - |
dc.date.accessioned | 2020-06-15T22:03:43Z | - |
dc.date.available | 2020-06-15T22:03:43Z | - |
dc.date.issued | 2004 | - |
dc.identifier.uri | https://repositorio.inpa.gov.br/handle/1/18889 | - |
dc.description.abstract | We investigated the physiological effects of dissolved organic matter (DOM) on sodium (Na +) transport in juvenile Oncorhynchus mykiss (∼2.5 g) in the presence and absence of simultaneous acute exposure to copper (Cu 2+; 0, 70, and 300 μg l -1). Trout were acclimated in either hardwater (∼1000 μM Ca 2+) or softwater (∼100 μM Ca 2+), and DOM was tested at approximately 8 mg C l -1 using a natural (NOM) and a commercial (AHA) source. Ion transport was evaluated based on kinetics estimates (maximum Na + uptake rates, J max; substrate affinity, K m) and unidirectional flux measurements (J in, J out, J net). J max was higher and unidirectional flux rates were greater in softwater-acclimated trout. Fish exposed to DOM alone in hardwater exhibited an increased Na + transport capacity indicated by both the kinetics (67% higher J max for AHA) and J in measurements (153% higher for AHA and 125% higher for NOM). In softwater, the effects of DOM alone on kinetic parameters and unidirectional flux rates were negligible. Cu 2+ affected Na + uptake by a mixed-type inhibition (both non-competitive and competitive). In hardwater, only K m was increased (i.e., affinity decreased), whereas in softwater, K m was increased and J max was decreased, with more marked effects at the higher Cu 2+ level. In hardwater, the stimulatory effect of AHA on J max persisted even in the presence of 300 μg l -1 Cu 2+, whereas both AHA and NOM prevented the increase in K m caused by Cu 2+; these effects were reflected in J in measurements. In softwater, AHA helped to protect against the increased K m caused by high Cu 2+, but there was no protection against the inhibition of J max. Unidirectional flux measurements indicated that in softwater, Cu 2+ inhibited J in at 70 μg l -1, whereas at 300 μg l -1 Cu 2+, J out was also stimulated. Fish were more affected by Cu 2+ in softwater, as indicated by the inability to control diffusive losses of Na + and a reduced ability to take up Na +, but in the presence of DOM, losses were better controlled at the end of 6 h exposure. We conclude that DOM has direct effects on the gills, as well as protecting fish against acute Cu 2+ toxicity. This occurs because DOM complexes Cu 2+, and because it acts on the transport and permeability properties of the gills. These effects differ depending on both water hardness and the nature of the DOM source. © 2004 Elsevier B.V. All rights reserved. | en |
dc.language.iso | en | pt_BR |
dc.relation.ispartof | Volume 70, Número 1, Pags. 63-81 | pt_BR |
dc.rights | Restrito | * |
dc.subject | Copper | en |
dc.subject | Dissolved Organic Matter | en |
dc.subject | Humic Acid | en |
dc.subject | Organic Matter | en |
dc.subject | Copper | en |
dc.subject | Dissolved Organic Matter | en |
dc.subject | Animals Experiment | en |
dc.subject | Binding Affinity | en |
dc.subject | Concentration Response | en |
dc.subject | Controlled Study | en |
dc.subject | Corhynchus Mykiss | en |
dc.subject | Exposure | en |
dc.subject | Gill | en |
dc.subject | Ion Transport | en |
dc.subject | Nonhuman | en |
dc.subject | Priority Journal | en |
dc.subject | Protection | en |
dc.subject | Rainbow Trout | en |
dc.subject | Sodium Transport | en |
dc.subject | Water Hardness | en |
dc.subject | Adaptation, Physiological | en |
dc.subject | Algorithms | en |
dc.subject | Animal | en |
dc.subject | Biomass | en |
dc.subject | Calcium | en |
dc.subject | Complex Mixtures | en |
dc.subject | Copper | en |
dc.subject | Dose-response Relationship, Drug | en |
dc.subject | Fresh Water | en |
dc.subject | Gills | en |
dc.subject | Ion Transport | en |
dc.subject | Kinetics | en |
dc.subject | Oncorhynchus Mykiss | en |
dc.subject | Organic Chemicals | en |
dc.subject | Sodium | en |
dc.subject | Water Pollutants, Chemical | en |
dc.subject | Water-electrolyte Balance | en |
dc.subject | Oncorhynchus | en |
dc.subject | Oncorhynchus Mykiss | en |
dc.subject | Salmonidae | en |
dc.title | Physiological action of dissolved organic matter in rainbow trout in the presence and absence of copper: Sodium uptake kinetics and unidirectional flux rates in hard and softwater | en |
dc.type | Artigo | pt_BR |
dc.identifier.doi | 10.1016/j.aquatox.2004.07.005 | - |
dc.publisher.journal | Aquatic Toxicology | pt_BR |
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