Aquaporin water channels in transepithelial fluid transport

Aquaporins (AQPs) are membrane water channels that are involved in a diverse set of functions in mammalian physiology including epithelial fluid transport, brain water balance, cell migration, cell proliferation, neuroexcitation, fat metabolism, epidermal hydration, and others. Phenotype analysis of...

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Bibliographic Details
Published inThe Journal of Medical Investigation Vol. 56; no. Supplement; pp. 179 - 184
Main Authors Tradtrantip, Lukmanee, Tajima, Masato, Li, Lihua, Verkman, AS
Format Journal Article
LanguageEnglish
Published Japan The University of Tokushima Faculty of Medicine 2009
Subjects
Animals
Aquaporins - genetics
Aquaporins - physiology
Biological Transport - physiology
Cell Membrane Permeability - physiology
Epithelial Cells - cytology
Epithelial Cells - physiology
epithelium
Exocrine Glands - cytology
Exocrine Glands - physiology
kidney
Kidney Tubules - cytology
Kidney Tubules - physiology
Mice
Mice, Knockout
Models, Animal
salivary gland
Water - metabolism
water channel
water transport
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Summary:Aquaporins (AQPs) are membrane water channels that are involved in a diverse set of functions in mammalian physiology including epithelial fluid transport, brain water balance, cell migration, cell proliferation, neuroexcitation, fat metabolism, epidermal hydration, and others. Phenotype analysis of knockout mice has demonstrated an important role for AQPs in transepithelial fluid transport in kidney tubules, salivary and airway submucosal glands, choroid plexus and ciliary epithelium. The physiological functions of these epithelia, such as absorption of glomerular filtrate by proximal tubule and secretion of saliva by salivary gland, involve rapid transcellular water transport across epithelial cell barriers. Studies in knockout mice have also provided evidence that AQPs are not physiologically important in some epithelia where they are expressed, including lacrimal gland, sweat gland, gallbladder, alveoli and airways. Rates of transepithelial fluid transport per unit membrane surface area in these epithelia are substantially lower than transepithelial fluid transport rates in proximal tubule and salivary gland. Pharmacological inhibition of AQP water permeability in epithelia, with consequent reduced fluid transport, offers potential therapy for human diseases involving water imbalance such as congestive heart failure, hypertension and glaucoma. J. Med. Invest. 56 Suppl.: 179-184, December, 2009
ISSN:1343-1420
1349-6867
DOI:10.2152/jmi.56.179