The effects of ototoxic drugs on mechano-electric transduction channels in chick cochlear hair cells.
The effects of ototoxic drugs on mechano-electrical transduction (MET) currents were investigated in dissociated cochlear hair cells of the chick, using a whole-cell patch-electrode voltage-clamp technique. Dihydrostreptomycin (DHSM) and cisplatin (cis-dichlorodiammine platinum II, CDDP) blocked the MET channel in a dose- and voltage-dependent manner. In contrast, acetyl salicylate did not suppress the MET current. At -50 mV, DHSM and CDDP blocked the MET channel with a Hill coefficient of 0.93 and 2.1, respectively. These findings suggest that a single DHSM molecule or more than one CDDP molecule binds to a single MET channel.
Kimitsuki
T
T
Department of Otorhinolaryngology, Faculty of Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812, Japan.
Nakagawa
T
T
Hisashi
K
K
Komune
S
S
Uemura
T
T
D000818:Animals; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000493:pharmacokinetics*; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000493:pharmacokinetics*; D002645:Chickens; D002945:Cisplatin / Q000009:adverse effects* / Q000493:pharmacokinetics*; D003051:Cochlea / Q000187:drug effects* / Q000378:metabolism*; D004096:Dihydrostreptomycin Sulfate / Q000009:adverse effects* / Q000493:pharmacokinetics*; D004305:Dose-Response Relationship, Drug; D006198:Hair Cells, Auditory / Q000187:drug effects* / Q000378:metabolism*; D018408:Patch-Clamp Techniques / Q000379:methods; D015398:Signal Transduction / Q000187:drug effects*
D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D002945:Cisplatin; D004096:Dihydrostreptomycin Sulfate