Localization of aquaporins 1, 2, and 3 and vasopressin type 2 receptor in the mouse inner ear

Abstract

Conclusion: It is suggested that aquaporins (AQPs) 1, 2, and 3, and vasopressin type 2 receptors (V2Rs) in the fluid transporting cells, such as stria vascularis, vestibular dark and transitional cells, and endolymphatic sac epithelial cells, have an important role in fluid transport in the inner ear, while those in the sensory and ganglion cells may play a functional role in the sensory cell transduction system. Objective: To analyze expression of AQP1, AQP2, and AQP3 as well as V2Rs in the normal mouse inner ear. Methods: CBA/J mice were used in this study. Localization of AQP1, AQP2, AQP3, and V2Rs in the inner ear, i.e. cochlea, vestibular end organs, and endolymphatic sac, was investigated by immunohistochemistry. Results: The results show that AQP1, AQP2, AQP3, and V2Rs are abundantly distributed in many inner ear structures, i.e. stria vascularis, inner and outer hair cells, spiral ganglion cells, vestibular sensory and ganglion cells, vestibular dark and transitional cells, and the endolymphatic sac.

Keywords::

• Immunohistochemistry
• fluid transport
• sensory cell transduction

Acknowledgment

This study was supported by a Health and Labor Science Research Grant for Research on Specific Diseases (Vestibular Disorders) from the Ministry of Health, Labor and Welfare, Japan (2011), a Grant-in-Aid for Scientific Research (22591881) provided by the Ministry of Education, Science and Culture, Japan, and also by the Swedish Medical Research Council, Uppsala University, and Akademiska sjukhuset (Uppsala, Sweden).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.