TY - JOUR
T1 - Aquaporins in complex tissues. II. Subcellular distribution in respiratory and glandular tissues of rat
AU - Nielsen, Søren
AU - King, Landon S.
AU - Christensen, Birgitte Mønster
AU - Acre, Peter
PY - 1997
Y1 - 1997
N2 - The molecular pathways for fluid transport in pulmonary, oral, and nasal tissues are still unresolved. Here we use immunocytochemistry and immunoelectron microscopy to define the sites of expression of four aquaporins in the respiratory tract and glandular epithelia, where they reside in distinct, nonoverlapping sites. Aquaporin-1 (AQP1) is present in apical and basolateral membranes of bronchial, tracheal, and nasopharyngeal vascular endothelium and fibroblasts. AQP5 is localized to the apical plasma membrane of type I pneumocytes and the apical plasma membranes of secretory epithelium in upper airway and salivary glands. In contrast, AQP3 is present in basal cells of tracheal and nasopharyngeal epithelium and is abundant in basolateral membranes of surface epithelial cells of nasal conchus. AQP4 resides in basolateral membranes of columnar cells of bronchial, tracheal, and nasopharyngeal epithelium; in nasal conchus AQP4 is restricted to basolateral membranes of a subset of intra- and subepithelial glands. These sites of expression suggest that transalveolar water movement, modulation of airway surface liquid, air humidification, and generation of nasopharyngeal secretions involve a coordinated network of aquaporin water channels.
AB - The molecular pathways for fluid transport in pulmonary, oral, and nasal tissues are still unresolved. Here we use immunocytochemistry and immunoelectron microscopy to define the sites of expression of four aquaporins in the respiratory tract and glandular epithelia, where they reside in distinct, nonoverlapping sites. Aquaporin-1 (AQP1) is present in apical and basolateral membranes of bronchial, tracheal, and nasopharyngeal vascular endothelium and fibroblasts. AQP5 is localized to the apical plasma membrane of type I pneumocytes and the apical plasma membranes of secretory epithelium in upper airway and salivary glands. In contrast, AQP3 is present in basal cells of tracheal and nasopharyngeal epithelium and is abundant in basolateral membranes of surface epithelial cells of nasal conchus. AQP4 resides in basolateral membranes of columnar cells of bronchial, tracheal, and nasopharyngeal epithelium; in nasal conchus AQP4 is restricted to basolateral membranes of a subset of intra- and subepithelial glands. These sites of expression suggest that transalveolar water movement, modulation of airway surface liquid, air humidification, and generation of nasopharyngeal secretions involve a coordinated network of aquaporin water channels.
KW - Alveolus nasopharyngeal epithelium
KW - Immunocytochemistry
KW - Immunoelectron microscopy
KW - Secretory glands
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UR - http://www.scopus.com/inward/citedby.url?scp=0030657804&partnerID=8YFLogxK
U2 - 10.1152/ajpcell.1997.273.5.c1549
DO - 10.1152/ajpcell.1997.273.5.c1549
M3 - Article
C2 - 9374640
AN - SCOPUS:0030657804
VL - 273
SP - C1549-C1561
JO - American Journal of Physiology
JF - American Journal of Physiology
SN - 0363-6143
IS - 5 42-5
ER -