Expression of the Osmotically Responsive Cationic Channel TRPV4 in the Endolymphatic Sac

Abstract

The immunohistochemical expression pattern and the physiological role of transient receptor potential vanilloid (TRPV) 4 in the endolymphatic sac were investigated. TRPV4 was expressed predominantly in the apical membrane of mitochondria-rich cells, and cell volume regulation by TRPV4 was observed in a tissue culture of the rat endolymphatic sac. TRPV4 was also present in the endolymphatic sacs of patients with vestibular schwannoma and with Ménière's disease. TRPV4 is assumed to play a role as an osmoreceptor in cell and fluid volume regulation in the human endolymphatic sac.