title: Measurement of the endolymphatic sac potential in human.
abstract: In this study, we measured human endolymphatic sac potential (ESP) in 8 patients with vestibular schwannoma and in five patients with Ménière's disease during surgery. ESP was measured with a glass electrode filled with 154 mM NaCl and with an outside tip diameter ranging from 2 to 3 microm. The mean value of human ESP in patients with vestibular schwannoma was +13.3+/-1.9 mV. Since electron microscopy showed that the endolymphatic sacs of the eight patients with vestibular schwannoma were normal in the ultrastructures the value can be close to normal human ESP. While in Ménière's disease, three cases showed low potentials and two cases showed almost the same values observed as in the eight patients with vestibular schwannoma. In the two cases with Ménière's disease, the epithelial cells of the endolymphatic sac were preserved. Our study can be considered as the first successful measurement of human ESP and revealed the existence of Ménière's disease having normal endolymphatic sac in function as well as morphology.
authors.affiliation: Division of Otorhinolaryngology, Department of Translational Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki, Japan. h-kumagami@bun.bbiq.jp
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Kumagami
authors.forename: Fujinobu
authors.initials: F
authors.lastname: Tanaka
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Dotsu
authors.forename: Haruo
authors.initials: H
authors.lastname: Yoshida
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ohsato
authors.forename: Motoyasu
authors.initials: M
authors.lastname: Katsura
authors.forename: Ryota
authors.initials: R
authors.lastname: Oku
authors.forename: Koichiro
authors.initials: K
authors.lastname: Shigeno
authors.forename: Haruo
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D000368:Aged; D004594:Electrophysiology; D004712:Endolymphatic Sac / Q000473:pathology / Q000503:physiopathology*; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008575:Meniere Disease / Q000473:pathology / Q000503:physiopathology*; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000473:pathology / Q000503:physiopathology*