Aquaporins (AQPs) is a novel family of membrane protein which is in charge of the transportation of water across the membranes. It has been testified that AQPs may be related to many physiological functions and pathophysiological disorders. In lung, 6 subtypes of AQPs were found, 4 of which have been located in certain tissue. AQP1, AQP3, AQP4 and AQP5 are located in upper respiratory tract and may contribute to the mucus production, bronchial moisturizing and gland secretion. AQP1 and AQP5 are located in lower respiratory tract and may participate in directing the water movement across the blood-gas barrier. AQPs in natal lung may be an important factor to accelerate the reabsorption of the lung liquid. In adult, some diseases such as asthma, pulmonary edema, adult respiratory distress syndrome, which have been considered unbalanced water movement, may be also concerned with AQPs. The relationship between lung edema and AQPs have not been elucidated in details. It should be verified how AQPs work in more organs and tissues as well as in some diseases.
