uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Regulation of the perilymphatic-endolymphatic water shunt in the cochlea by membrane translocation of aquaporin-5
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
Show others and affiliations
2015 (English)In: Pflügers Archiv: European Journal of Physiology, ISSN 0031-6768, E-ISSN 1432-2013, Vol. 467, no 12, 2571-2588 p.Article in journal (Refereed) Published
Abstract [en]

Volume homeostasis of the cochlear endolymph depends on radial and longitudinal endolymph movements (LEMs). LEMs measured in vivo have been exclusively recognized under physiologically challenging conditions, such as experimentally induced alterations of perilymph osmolarity or endolymph volume. The regulatory mechanisms that adjust LEMs to the physiological requirements of endolymph volume homeostasis remain unknown. Here, we describe the formation of an aquaporin (AQP)-based "water shunt" during the postnatal development of the mouse cochlea and its regulation by different triggers. The final complementary expression pattern of AQP5 (apical membrane) and AQP4 (basolateral membrane) in outer sulcus cells (OSCs) of the cochlear apex is acquired at the onset of hearing function (postnatal day (p)8-p12). In vitro, hyperosmolar perfusion of the perilymphatic fluid spaces or the administration of the muscarinic agonist pilocarpine in cochlear explants (p14) induced the translocation of AQP5 channel proteins into the apical membranes of OSCs. AQP5 membrane translocation was blocked by the muscarinic antagonist atropine. The muscarinic M3 acetylcholine (ACh) receptor (M3R) was identified in murine OSCs via mRNA expression, immunolabeling, and in vitro binding studies using an M3R-specific fluorescent ligand. Finally, the water shunt elements AQP4, AQP5, and M3R were also demonstrated in OSCs of the human cochlea. The regulation of the AQP4/AQP5 water shunt in OSCs of the cochlear apex provides a molecular basis for regulated endolymphatic volume homeostasis. Moreover, its dysregulation or disruption may have pathophysiologic implications for clinical conditions related to endolymphatic hydrops, such as Ménière's disease.

Place, publisher, year, edition, pages
2015. Vol. 467, no 12, 2571-2588 p.
National Category
URN: urn:nbn:se:uu:diva-265768DOI: 10.1007/s00424-015-1720-6ISI: 000365187500016PubMedID: 26208470OAI: oai:DiVA.org:uu-265768DiVA: diva2:866516
Available from: 2015-11-03 Created: 2015-11-03 Last updated: 2015-12-28Bibliographically approved

Open Access in DiVA

fulltext(6526 kB)8 downloads
File information
File name FULLTEXT01.pdfFile size 6526 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Liu, WeiRask-Andersen, Helge
By organisation
Otolaryngology and Head and Neck Surgery
In the same journal
Pflügers Archiv: European Journal of Physiology

Search outside of DiVA

GoogleGoogle Scholar
Total: 8 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 105 hits
ReferencesLink to record
Permanent link

Direct link