title: Delayed shortening and shrinkage of cochlear outer hair cells.
abstract: Slow shortening of cochlear outer hair cells has been speculated to modify cochlear sensitivity. Tetanic electrical field stimulation of isolated outer hair cells from guinea pigs shortened the cells for 2-3 min. Electrical stimulation reduced cell length and volume (-13.5 +/- 1.5 and -37.3 +/- 3.0% of initial values, respectively, n = 16) and decreased the intracellular Cl- concentration. Cytochalasin B (100 microM) inhibited electrical stimulation-induced shortening but not volume reduction. The following chemicals or manipulations inhibited the responses: 10 microM furosemide, 0.1 mM 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), 1 mM anthracene-9-carboxylic acid (AC9), 25 mM tetraethylammonium, 2.3 microM charybdotoxin (ChTX), 250 nM omega-conotoxin, and Ca(2+)-free medium. These findings suggest that both electrical stimulation-induced shortening and shrinkage of outer hair cells result not only from an actin-mediated contractile force, but also from Cl- efflux through furosemide-, DIDS-, and AC9-sensitive Cl- channels, and K+ efflux through ChTX-sensitive K+ channels.
authors.affiliation: Department of Pharmacology, Kansai Medical University, Osaka, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Ohnishi
authors.forename: M
authors.initials: M
authors.lastname: Hara
authors.forename: M
authors.initials: M
authors.lastname: Inoue
authors.forename: T
authors.initials: T
authors.lastname: Yamashita
authors.forename: T
authors.initials: T
authors.lastname: Kumazawa
authors.forename: A
authors.initials: A
authors.lastname: Minato
authors.forename: C
authors.initials: C
authors.lastname: Inagaki
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002712:Chlorides / Q000378:metabolism; D003571:Cytochalasin B / Q000494:pharmacology; D004558:Electric Stimulation; D004594:Electrophysiology; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D011188:Potassium / Q000502:physiology; D015221:Potassium Channels / Q000378:metabolism; D011804:Quinolines; D013997:Time Factors
chemical_list: D000199:Actins; D002712:Chlorides; D015221:Potassium Channels; D011804:Quinolines; C078229:N-(6-methoxyquinolyl)acetoethyl ester; D003571:Cytochalasin B; D011188:Potassium; D002118:Calcium