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Immunolocalisation of sodium/proton exchanger-like proteins in the gills of elasmobranchs

Version 2 2024-06-17, 03:54
Version 1 2014-10-27, 16:27
journal contribution
posted on 2024-06-17, 03:54 authored by S Edwards, John Donald, T Toop, M Donowitz, CM Tse
Na+/H+ exchangers are integral membrane proteins that exchange Na+ and H+ across cell membranes. The Na+/H+ exchangers 2 and 3 are epithelial isoforms in mammals and contribute to acid–base homeostasis. The gills of fishes, including elasmobranchs, are also associated with acid/base balance, and are probably the primary acid/base regulatory organ. This study examines the presence of Na+/H+ exchangers 2 and 3 using immunohistochemistry and immunoblotting in the gills of four species of elasmobranchs, the banjo ray (Trygonorrhina fasciata), southern eagle ray (Myliobatis australis), the gummy shark (Mustelus antarcticus) and the Australian angel shark (Squatina australis) using heterologous antibodies. Na+/H+ exchanger 2-like immunoreactivity was observed in the gills of the banjo ray, eagle ray and angel shark. In the banjo and eagle rays, this Na+/H+ exchanger-like immunoreactivity co-localised with immunoreactivity to Na+/K+-ATPase, a marker for the mitochondrial-rich cells of fishes. Na+/H+ exchanger 3-like immunoreactivity was only observed in the gills of the angel and gummy sharks, some Na+/H+ exchanger 3-like cells also showed Na+/K+-ATPase immunoreactivity. However, immunoblotting of banjo and eagle ray gill membranes demonstrated Na+/H+ exchanger 3-like immunoreactivity, which was not consistent with the immunohistochemical results. These data demonstrate the presence of epithelial Na+/H+ exchangers 2 and 3 in the gills of elasmobranchs and a link with acid/base regulation is suggested.

History

Journal

Comparative biochemistry and physiology - part a: molecular & integrative physiology

Volume

131

Pagination

257-265

Location

New York, N.Y.

ISSN

1095-6433

eISSN

1531-4332

Language

eng

Publication classification

C1 Refereed article in a scholarly journal

Copyright notice

2002, Elsevier Science Inc

Issue

2

Publisher

Elsevier Science Inc.