Effects of copper on gill structure and transport function in the rainbow trout, Oncorhynchus mykiss.
Effects of copper were studied in freshwater adapted rainbow trout using the perfused head preparation. In its monovalent chemical form, copper at millimolar concentrations had no significant effects on Na+ and water transport. By contrast, the divalent form produced an increase in gill perfusion pressure, a significant reduction in Na+ influx and water fluxes and reversed Na+ net flux. Observations by light microscopy showed important cell damage (oedema, mucus production, cellular desquamation). By electron microscopy there was smoothing of apical membranes, swelling of the tubular system and destruction of mitochondria. The Na, K-ATPase activity was totally suppressed and residual ATPase activity largely inhibited by 1 mM Cu2+. There was inhibition of the Na,K-ATPase activity with an IC50 of approximately 10 microM of total copper (free and bound cupric fractions). As active sodium transport is located on the secondary lamellae, our results show that its entry mechanism is inhibited at that level by cupric ions only. Results are discussed in relation to hydromineral balance of the trout.
Sola
F
F
Laboratoire de Physiologie Cellulaire et Comparée, Université de Nice Sophia Antipolis, France.
Isaia
J
J
Masoni
A
A
D000704:Analysis of Variance; D000818:Animals; D001681:Biological Assay; D001693:Biological Transport, Active / Q000187:drug effects; D001934:Branchial Region / Q000378:metabolism / Q000473:pathology; D003300:Copper / Q000633:toxicity*; D005618:Fresh Water; D005880:Gills / Q000166:cytology / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure; D007928:Lethal Dose 50; D008854:Microscopy, Electron; D008861:Microsomes / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D008933:Mitochondrial Swelling / Q000187:drug effects; D017686:Oncorhynchus mykiss; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D003300:Copper; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase