Format

Send to

Choose Destination
See comment in PubMed Commons below
Toxicol Appl Pharmacol. 1999 Aug 15;159(1):1-8.

ATP-dependent silver transport across the basolateral membrane of rainbow trout gills.

Author information

1
Hatherly Laboratories, University of Exeter, Exeter, EX4 4PS, United Kingdom.

Abstract

Silver has been shown to be extremely toxic to freshwater teleosts, acting to inhibit Na(+) uptake at the gills, due to the inactivation of branchial Na(+)/K(+)-ATPase activity. However, the gills are also a route by which silver may enter the fish. Therefore, this study focuses on the mechanism of transport of this nonessential metal across the basolateral membrane of the gill cell, using basolateral membrane vesicles (BLMV) prepared from the gills of freshwater rainbow trout. Uptake of silver by BLMV was via a carrier-mediated process, which was ATP-dependent, reached equilibium over time, and followed Michaelis-Menten kinetics, with maximal transport capacity (V(max)) of 14.3 +/- 5.5 (SE) nmol mg membrane protein(-1) min(-1) and an affinity (K(m)) of 62.6 +/- 43.7 microM, and was inhibited by 100 microM sodium orthovanadate (Na(3)VO(4)). The ionophore monensin (10 microM) released transported silver from the BLMV. Acylphosphate intermediates, of a 104 kDa size, were formed from the BLMV preparations in the presence of ATP plus Ag. These results demonstrate that there is a P-type ATPase present in the basolateral membrane of the gills of rainbow trout that can actively transport silver, a process which will remove this heavy metal from its site of toxic action, the gill.

PMID:
10448119
DOI:
10.1006/taap.1999.8706
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center