title: Isolation of and calcium kinetics in cochlear inner hair cells of the guinea pig.
abstract: Single inner hair cells of the guinea pig cochlea were isolated using enzymatic and mechanical techniques. The intracellular free calcium ion concentrations [( Ca2+]i) of the isolated inner hair cells were determined using the Ca2+ sensitive dye fura-2 and digital imaging microscopy. In the presence of 1 micron ionomycin, a Ca2+ ionophore, there was an irreversible increase in [Ca2+]i. The 150 mM KCl stimulation, which induces a depolarization, resulted in a temporary increase in [Ca2+]i. This increase in [Ca2+]i was not observed under conditions of depolarization, in Ca(2+)-free medium. These observations are interpreted to mean that the [Ca2+]i during membrane depolarization mainly originates from an influx of extracellular Ca2+ into the cytoplasm.
authors.affiliation: Department of Otolaryngology, Kansai Medical University, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamashita
authors.forename: H
authors.initials: H
authors.lastname: Amano
authors.forename: M
authors.initials: M
authors.lastname: Ohtani
authors.forename: N
authors.initials: N
authors.lastname: Harada
authors.forename: T
authors.initials: T
authors.lastname: Kumazawa
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002469:Cell Separation; D016257:Fura-2 / Q000378:metabolism; D006168:Guinea Pigs; D006199:Hair Cells, Auditory, Inner / Q000187:drug effects / Q000378:metabolism*; D007091:Image Processing, Computer-Assisted; D007700:Kinetics; D008856:Microscopy, Fluorescence
chemical_list: D002118:Calcium; D016257:Fura-2