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

• Main Authors: S Edwards, John Donald, Marie-Therese Toop, M Donowitz, C M Tse
• Format: Other Non-Article Part of Journal/Newspaper
• Language: unknown
• Published: 2002
• Subjects: Physiology; Zoology; acid\/base regulation; elasmobranch; gills; sodium\/proton exchanger; Na+\/H+ exchanger (NHE); mitochondria-rich cells; Science & Technology; Life Sciences & Biomedicine; Biochemistry & Molecular Biology; DOGFISH SQUALUS-ACANTHIAS; ACID-BASE-BALANCE; NA+\/H+ EXCHANGER; MOLECULAR-CLONING; FUNCTIONAL EXPRESSION; BRANCHIAL EPITHELIUM; FISH; LOCALIZATION; TRANSPORT; ATPASE; Antarc*; antarcticus; Squalus acanthias
• Online Access: http://hdl.handle.net/10536/DRO/DU:30001696; https://figshare.com/articles/journal_contribution/Immunolocalisation_of_sodium_proton_exchanger-like_proteins_in_the_gills_of_elasmobranchs/20531568

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.