title: The effect of copper on osmoregulation in the freshwater amphipod Gammarus pulex.
abstract: The influence of copper on osmoregulation in the freshwater amphipod Gammarus pulex was determined from the analysis of water permeability, haemolymph sodium concentration, sodium influx and gill Na(+)/K(+) ATPase and Mg(2+) ATPase activity. Exposure to nominal copper concentrations of 100 microg l(-1) or greater caused a significant reduction in both haemolymph sodium concentration and sodium influx within 4 h. Measurements of water permeability, expressed as the half-time of exchange of body water (t(1/2)), excluded structural gill damage as the cause of this fall in haemolymph sodium. Copper at 10 microg l(-1) or above in the assay solution significantly reduced gill Na(+)/K(+) ATPase activity. In contrast gill Mg(2+) ATPase activity was markedly less affected by copper. These differences in enzyme sensitivity were considered with respect to the potential mechanisms of copper toxicity.
authors.affiliation: School of Science, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Brooks
authors.forename: Chris Lloyd
authors.initials: CL
authors.lastname: Mills
mesh_terms: D033304:Amphipoda / Q000502:physiology*; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000037:antagonists & inhibitors; D003300:Copper / Q000494:pharmacology*; D005618:Fresh Water; D005880:Gills / Q000201:enzymology; D006458:Hemolymph / Q000378:metabolism; D009994:Osmolar Concentration; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors; D014882:Water-Electrolyte Balance / Q000187:drug effects*
chemical_list: D003300:Copper; D012964:Sodium; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase