Aquaporins in the adult mouse submandibular and sublingual salivary glands.

Aquaporins (AQPs) is a family of membrane bound water channels found in most tissues. In addition to contribute to transepithelial water movement, AQPs are shown to be involved in a variety of processes such as proliferation, cell migration, and apoptosis. In salivary glands, it is well known that AQP5 plays an important role in fluid secretion. In recent years, several AQPs that demonstrate specific expression trends during development have been found in the mouse submandibular gland (SMG). In this study, we wanted to further investigate the presence and localization of the AQP family in the adult mouse SMG in addition to the less studied sublingual gland. Real time PCR and Western blot demonstrated the presence of AQP3, 4, 8, 9, and 11 transcripts and proteins. AQP1 and AQP7 were shown to be localized in endothelial cells, while AQP4 was found in the satellite cells of the parasympathetic ganglia in both glands. The result from this study shows that AQPs are found in defined subpopulations of cells in salivary glands, providing novel insights to their specific roles in salivary glands.