Water transport across epithelial and endothelial barriers in bronchopulmonary tissues occurs during airway hydration, alveolar fluid transport, and submucosal gland secretion. Many of the tissues involved in these processes are highly water permeable and express aquaporin (AQP) water channels. AQP1 is expressed in microvascular endothelia throughout the lung and airways, AQP3 in epithelia in l...

In the colony of Sprague-Dawley (SD) strain, we found that there were rats expressing a mutant AQP5, which has a point mutation at nt 308 (G308A), leading to a replacement of (103)Gly with (103)Asp in the 3rd transmembrane domain. The mutant molecule scarcely expressed in the acinar cells, probably because of ineffective trafficking. The mutant molecule, however, showed normal water permeabilit...

Multiple physiological fluid movements are involved in vision. Here we define the cellular and subcellular sites of aquaporin (AQP) water transport proteins in human and rat eyes by immunoblotting, high-resolution immunocytochemistry, and immunoelectron microscopy. AQP3 is abundant in bulbar conjunctival epithelium and glands but is only weakly present in corneal epithelium. In contrast, AQP5 i...

The aquaporin (AQP) family of water channels is distributed ubiquitously in many epithelia and plays a fundamental role in transmembrane water transport. The aim of this study is to identify the water transport pathway in pancreatic duct cells where most of the HCO-rich fluid originates. Using digital videomicroscopy, we measured the osmotic water permeability (P(f)) of pancreatic duct epitheli...

The current standard of care for head and neck cancer includes surgical resection of the tumor followed by targeted head and neck radiation. This radiotherapy results in a multitude of negative side effects in adjacent normal tissues. Autophagy is a cellular mechanism that could be targeted to ameliorate these side effects based on its role in cellular homeostasis. In this study, we utilized At...

Aquaporins (AQPs) facilitate water transport across epithelia and play an important role in normal physiology and disease in the human airways. We used in situ hybridization and immunofluorescence to determine the expression and cellular localization of AQPs 5, 4, and 3 in human airway sections. In nose and bronchial epithelia, AQP5 is expressed at the apical membrane of columnar cells of the s...

Recent data suggest a possible involvement of Aquaporins (AQPs) in pain transmission. AQPs are small membrane channel proteins involved in osmoregulation and, to date, AQP1, AQP2, AQP3, AQP4, AQP5, AQP8 and AQP9 have been found in the nervous system. Nevertheless only AQP1, AQP2 and AQP4 seem to be involved in nociception.In this review, direct and indirect evidences of the role of AQPs in pain...