Nacl Uptake by the Branchial Epithelium in Freshwater Teleost Fish: An Immunological Approach to Ion-Transport Protein Localization
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- Jonathan M. Wilson
- University of British Columbia 1 Department of Zoology , , Vancouver, Canada V6T 1Z4
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- Pierre Laurent
- 2 Centre Ecologie et Physiologie Energetique, Centre National Recherche Scientifique, Strasbourg 67037, France
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- Bruce L. Tufts
- Queens University 3 Department of Biology , , Kingston, Ontario, Canada K7L 3N6
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- Dale J. Benos
- University of Alabama at Birmingham 4 Departments of Biophysics and Physiology , , AL 35294-0005, USA
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- Mark Donowitz
- Johns Hopkins University 5 Departments of Medicine and Physiology, GI Unit , , Baltimore, MD 21205-2195, USA
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- A. Wayne Vogl
- University of British Columbia 6 Department of Anatomy , , Vancouver, British Columbia, Canada V6T 1Z3
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- David J. Randall
- University of British Columbia 1 Department of Zoology , , Vancouver, Canada V6T 1Z4
説明
<jats:title>ABSTRACT</jats:title> <jats:p>Teleost fishes, living in fresh water, engage in active ion uptake to maintain ion homeostasis. Current models for NaCl uptake involve Na+uptake via an apical amiloride-sensitive epithelial Na+channel (ENaC), energized by an apical vacuolar-type proton pump (V-ATPase) or alternatively by an amiloride-sensitive Na+/H+exchange (NHE) protein, and apical Cl−uptake mediated by an electroneutral, SITS-sensitive Cl−/HCO3−anion-exchange protein. Using non-homologous antibodies, we have determined the cellular distributions of these ion-transport proteins to test the predicted models. Na+/K+-ATPase was used as a cellular marker for differentiating branchial epithelium mitochondria-rich (MR) cells from pavement cells. In both the freshwater tilapia (Oreochromis mossambicus) and rainbow trout (Oncorhynchus mykiss), V-ATPase and ENaC-like immunoreactivity co-localized to pavement cells, although apical labelling was also found in MR cells in the trout. In the freshwater tilapia, apical anion-exchanger-like immunoreactivity is found in the MR cells. Thus, a freshwater-type MR chloride cell exists in teleost fishes. The NHE-like immunoreactivity is associated with the accessory cell type and with a small population of pavement cells in tilapia.</jats:p>
収録刊行物
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- Journal of Experimental Biology
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Journal of Experimental Biology 203 (15), 2279-2296, 2000-08-01
The Company of Biologists