Inhibition of basolateral branchial Na{sup +}/K{sup +}-ATPase may be the key mechanism for silver toxicity in fish
- Univ. of Kentucky, Lexington, KY (United States). T.H. Morgan School of Biological Science
Recent studies of freshwater fish have indicated that the mechanism of silver toxicity may lie in the ability of the metal to compromise bronchial transport of Na{sup +} and Cl (Wood et al, 1994). As part of a study, investigating the physiological mechanisms of silver toxicity to marine fish, the effect of Ag{sup +} on Na{sup +}/K{sup +}-ATPase in isolated basolateral membranes (BLM) from gills of sea-water acclimated rainbow trout was analyzed. Silver inhibition of purified dog kidney Na{sup +}/K{sup +}-ATPase was studied in a pilot experiment and the results from this experiment were compared to those obtained for rainbow trout BLMS. Michaelis-Menten kinetics of Na{sup +}/K{sup +}-ATPase activity was performed during control conditions by varying the concentrations of Na+ and K+ in the assay medium while keeping the total salt concentration constant. Inhibition of Na{sup +}/K{sup +}-ATPase activities was investigated by adding 1 nM--1 {micro}M of Ag{sup +} to the medium. Assay conditions were optimized separately for dog and rainbow trout Na{sup +}/K{sup +}-ATPase. Results from both series indicate effect of Ag{sup +} at a concentration as low as 1 nM escalating to complete quenching at a Ag{sup +} activity of 1 {micro}M. These results suggest the key mechanism of silver toxicity in marine fish involves blockage of the Na{sup +}/K{sup +}-ATPase activity in the gill epithelium.
- OSTI ID:
- 392350
- Report Number(s):
- CONF-9511137-; ISBN 1-880611-03-1; TRN: IM9647%%204
- Resource Relation:
- Conference: 2. Society of Environmental Toxicology and Chemistry (SETAC) world conference, Vancouver (Canada), 5-9 Nov 1995; Other Information: PBD: 1995; Related Information: Is Part Of Second SETAC world congress (16. annual meeting): Abstract book. Global environmental protection: Science, politics, and common sense; PB: 378 p.
- Country of Publication:
- United States
- Language:
- English
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