Details
| Original language | English |
|---|---|
| Pages (from-to) | 865-7 |
| Number of pages | 3 |
| Journal | Pflugers Archiv European Journal of Physiology |
| Volume | 438 |
| Issue number | 6 |
| Publication status | Published - Nov 1999 |
Abstract
Gap junctional coupling of cochlear supporting cells is thought to be responsible for spatial potassium buffering of the microenvironment of outer hair cells (OHC). OHC of the organ of Corti are considered as the target of aminoglycoside-induced ototoxicity. Due to the proposed functional relationship between OHC and cochlear supporting cells we investigated a possible involvement of the supporting Hensen cells in the ototoxic effect of the aminoglycoside gentamicin. Isolated Hensen cell pairs were superfused by gentamicin-containing bath solutions. Using the double whole-cell patch-clamp method gentamicin (10 microM) inhibited gap junctional conductance by about 90%, whereas the membrane potential of about -27 mV remained unchanged. Since the inhibitory effect was suppressed by the addition of catalase, the gentamicin mediated effect probably is due to production of free radicals. It is proposed that formation of free radicals in supporting cells inhibits gap junctional coupling whereby the spatial potassium buffer mechanism and, thus, the fine tuning of the cochlear OHC is impaired.
Keywords
- Animals, Catalase/pharmacology, Cochlea/cytology, Dose-Response Relationship, Drug, Drug Combinations, Electric Conductivity, Gap Junctions/drug effects, Gentamicins/pharmacology, Guinea Pigs, Patch-Clamp Techniques
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Pflugers Archiv European Journal of Physiology, Vol. 438, No. 6, 11.1999, p. 865-7.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Inhibition of gap junctional coupling in cochlear supporting cells by gentamicin
AU - Todt, I
AU - Ngezahayo, A
AU - Ernst, A
AU - Kolb, H A
PY - 1999/11
Y1 - 1999/11
N2 - Gap junctional coupling of cochlear supporting cells is thought to be responsible for spatial potassium buffering of the microenvironment of outer hair cells (OHC). OHC of the organ of Corti are considered as the target of aminoglycoside-induced ototoxicity. Due to the proposed functional relationship between OHC and cochlear supporting cells we investigated a possible involvement of the supporting Hensen cells in the ototoxic effect of the aminoglycoside gentamicin. Isolated Hensen cell pairs were superfused by gentamicin-containing bath solutions. Using the double whole-cell patch-clamp method gentamicin (10 microM) inhibited gap junctional conductance by about 90%, whereas the membrane potential of about -27 mV remained unchanged. Since the inhibitory effect was suppressed by the addition of catalase, the gentamicin mediated effect probably is due to production of free radicals. It is proposed that formation of free radicals in supporting cells inhibits gap junctional coupling whereby the spatial potassium buffer mechanism and, thus, the fine tuning of the cochlear OHC is impaired.
AB - Gap junctional coupling of cochlear supporting cells is thought to be responsible for spatial potassium buffering of the microenvironment of outer hair cells (OHC). OHC of the organ of Corti are considered as the target of aminoglycoside-induced ototoxicity. Due to the proposed functional relationship between OHC and cochlear supporting cells we investigated a possible involvement of the supporting Hensen cells in the ototoxic effect of the aminoglycoside gentamicin. Isolated Hensen cell pairs were superfused by gentamicin-containing bath solutions. Using the double whole-cell patch-clamp method gentamicin (10 microM) inhibited gap junctional conductance by about 90%, whereas the membrane potential of about -27 mV remained unchanged. Since the inhibitory effect was suppressed by the addition of catalase, the gentamicin mediated effect probably is due to production of free radicals. It is proposed that formation of free radicals in supporting cells inhibits gap junctional coupling whereby the spatial potassium buffer mechanism and, thus, the fine tuning of the cochlear OHC is impaired.
KW - Animals
KW - Catalase/pharmacology
KW - Cochlea/cytology
KW - Dose-Response Relationship, Drug
KW - Drug Combinations
KW - Electric Conductivity
KW - Gap Junctions/drug effects
KW - Gentamicins/pharmacology
KW - Guinea Pigs
KW - Patch-Clamp Techniques
U2 - 10.1007/s004249900109
DO - 10.1007/s004249900109
M3 - Article
C2 - 10591076
VL - 438
SP - 865
EP - 867
JO - Pflugers Archiv European Journal of Physiology
JF - Pflugers Archiv European Journal of Physiology
SN - 0031-6768
IS - 6
ER -