Voltage-dependent channels in dissociated outer hair cells of the guinea pig.
Voltage-dependent channels in outer hair cells (OHCs) dissociated from the guinea pig cochlea were investigated by the use of a whole-cell patch-clamp technique. Two types of K+ current were recorded from OHCs. One was a slowly inactivating K+ current that was activated at a potential more positive than -30 mV. Another is a K+ current that was already activated at resting membrane potential. After suppressing both K+ currents, depolarizing voltage steps elicited a slowly inactivating inward current that was dependent on external Ca2+ and was indicative of an L-type Ca2+ channel in OHCs. Aminoglycoside antibiotics known to be ototoxic selectively inhibited the Ca2+ current.
Nakagawa
T
T
Department of Otorhinolayngology, Faculty of Medicine, Kyushu University, Fukuoka 812, Japan.
Kakehata
S
S
Akaike
N
N
Komune
S
S
Takasaka
T
T
Uemura
T
T
D000617:Aminoglycosides; D000818:Animals; D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D015220:Calcium Channels / Q000187:drug effects*; D005260:Female; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000187:drug effects*; D008297:Male; D018408:Patch-Clamp Techniques; D024642:Potassium Channels, Voltage-Gated / Q000187:drug effects*
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D015220:Calcium Channels; D024642:Potassium Channels, Voltage-Gated