Abstract
The aquaporins (water channels) are novel molecular transporters that permit water to across the epithelial and endothelial plasma membrane. Recent studies strongly suggest that an important contribution of aquaporin in the respiratory pathophysiology. This review introduces recent advances of aquaporin on fluid transport in the distal airway and lung. AQP1 expresses in microvascular endothelia in the pulmonary interstitium. AQP5 mainly exists on alveolar type I cells. AQP3 and AQP4 are at basolateral side of large and small airways. We established new biophysical and physiological methodologies that enable to evaluate active and passive water transport in human and animal distal airway. Gene knock out technique make it possible to estimate pathophysiological roles of aquaporins in murine organs. AQP1 and AQP5 had an important role in water permeability in lung, but did not in AQP3 and AQP4. All aquaporins we examined did not contribute to active ion and water transport in murine distal airway and lung. Further study requires to elucidate the role of aquaporins in airway and lung.
