Data/hora: 10/06/2024 10:05:17

Provedor de dados: | 5
País: | France
Título: | Ionic composition of endolymph in teleosts: Origin and importance of endolymph alkalinity
Autores: | Payan, P; Kossmann, Hans; Watrin, A; Mayer-gostan, N; Boeuf, Gilles.
Data: | 1997-07
Ano: | 1997
Palavras-chave: | Teleost; Inner ear; Saccular epithelium; Proton secretion; Otolith; Biocalcification; Trout; Oncorhynchus mykiss; Turbot; Scophthalmus maximus.
Resumo: | Ionic (Na+, K+, Cl-, PO43-, pH), total CO2, total calcium and protein concentrations in the plasma and endolymph of the inner ear were compared in trout Oncorhynchus mykiss and turbot Scophthalmus maximus. In both species, saccular endolymph was characterized by high levels of K+ and total CO2 and in trout by an alkaline pH, The kinetic characteristics of proton secretion across the saccular epithelium of trout were investigated using a titration technique in which isolated saccules were mounted as closed sacs. The rate of proton secretion depends strongly on the pH of the Ringer's solution and secretion stops at a pH below 7.2, Proton secretion is driven by an energy-dependent mechanism involving basolateral ouabain-sensitive Na+/K+ exchangers. Proton secretion was partially inhibited by acetazolamide and completely inhibited in Na+-free Ringer or in the presence of 1 mmol l(-1) amiloride. A cellular model stressing the importance of proton exchange through the saccular epithelium is proposed to explain the regulation of endolymph pH, a crucial factor for the deposition of otolith calcium.
Tipo: | Text
Idioma: | Inglês

Identificador:

http://archimer.ifremer.fr/doc/00336/44695/44987.pdf

http://archimer.ifremer.fr/doc/00336/44695/

Editor: | Company Of Biologists Ltd
Formato: | application/pdf
Fonte: | Journal Of Experimental Biology (0022-0949) (Company Of Biologists Ltd), 1997-07 , Vol. 200 , N. 13 , P. 1905-1912

Fonte:

The Company of Biologists Limited 1997

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