title: Maxi-K+ channel in plasma membrane of basal cells dissociated from the stria vascularis of gerbils.
abstract: The plasma membrane of isolated strial basal cells has been probed for conductive pathways by the patch-clamp single-channel recording technique. Maxi-K+ channels were identified in 28 excised patches (i.e., 29%) out of 95, and these active patches each contained an average of 2.4 channel activities. In the cell-attached mode, activity of the maxi-K+ channel was also observed. Properties of the maxi-K+ channel thus revealed include: (1) linear I-V relations with 150 mM K+ on both sides of the membrane, (2) a unit conductance of 246.2 +/- 4.0 pS (n = 14). (3) Ca2- sensitivity, (4) activation by membrane depolarization. (5) a complete block by Ba2- (2 mM) from either side of the membrane. (6) a flickering block by quinine (0.1 mM) or verapamil (0.1 mM) from either side of the membrane, and (7) a complete block by tetraethylammonium (1 mM) from the outside only. The maxi-K+ channel may play a role in the generation of endocochlear potentials.
authors.affiliation: Department of Physiology, Kochi Medical School, Nankoku, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Takeuchi
authors.forename: A
authors.initials: A
authors.lastname: Irimajiri
mesh_terms: D000827:Animal Welfare; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D005849:Gerbillinae; D017136:Ion Transport; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000378:metabolism*; D012984:Software; D013316:Stria Vascularis / Q000166:cytology* / Q000378:metabolism
chemical_list: D026902:Potassium Channel Blockers; D015221:Potassium Channels; D011188:Potassium