Details
| Original language | English |
|---|---|
| Pages (from-to) | 107-14 |
| Number of pages | 8 |
| Journal | The journal of membrane biology |
| Volume | 181 |
| Issue number | 2 |
| Publication status | Published - 15 May 2001 |
Abstract
The double whole-cell patch-clamp configuration was applied to analyze gap junctional conductance (Gj) of isolated pairs of cochlear supporting Hensen cells of guinea pig under control conditions and in the presence of hydrogen peroxide (H2O2). Under control conditions, the dependence of Gj on transjunctional voltage (Vj) appeared to vary between different cell pairs with a maximum value of about 40 nS at Vj close to 0 mV. The voltage dependence and the maximum amplitude of Gj stayed constant for at least 2 hr. Addition of H2O2 to the bath at concentrations above 0.08 mm caused a significant decrease of Gj, but the membrane potential of about -30 mV was not affected. In parallel, intracellular free calcium ([Ca2+]i) was followed using fura-2. At 0.8 mm H2O2, a sustained increase of [Ca2+]i was observed, while 0.08 mm H2O2 evoked an oscillating-like behavior of [Ca2+]i. We propose that the H2O2-evoked inhibition of gap junctional coupling of Hensen cells is closely related to pathophysiological conditions such as noise- induced hearing loss, aminoglycoside-related ototoxicity and presbycusis, which are known to be associated with production of free radicals.
Keywords
- Animals, Calcium/metabolism, Calcium Signaling/drug effects, Cochlea/cytology, Electric Conductivity, Gap Junctions/drug effects, Guinea Pigs, Hydrogen Peroxide/pharmacology, Intracellular Fluid/drug effects, Patch-Clamp Techniques
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In: The journal of membrane biology, Vol. 181, No. 2, 15.05.2001, p. 107-14.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Hydrogen peroxide inhibits gap junctional coupling and modulates intracellular free calcium in cochlear Hensen cells
AU - Todt, I
AU - Ngezahayo, A
AU - Ernst, A
AU - Kolb, H A
PY - 2001/5/15
Y1 - 2001/5/15
N2 - The double whole-cell patch-clamp configuration was applied to analyze gap junctional conductance (Gj) of isolated pairs of cochlear supporting Hensen cells of guinea pig under control conditions and in the presence of hydrogen peroxide (H2O2). Under control conditions, the dependence of Gj on transjunctional voltage (Vj) appeared to vary between different cell pairs with a maximum value of about 40 nS at Vj close to 0 mV. The voltage dependence and the maximum amplitude of Gj stayed constant for at least 2 hr. Addition of H2O2 to the bath at concentrations above 0.08 mm caused a significant decrease of Gj, but the membrane potential of about -30 mV was not affected. In parallel, intracellular free calcium ([Ca2+]i) was followed using fura-2. At 0.8 mm H2O2, a sustained increase of [Ca2+]i was observed, while 0.08 mm H2O2 evoked an oscillating-like behavior of [Ca2+]i. We propose that the H2O2-evoked inhibition of gap junctional coupling of Hensen cells is closely related to pathophysiological conditions such as noise- induced hearing loss, aminoglycoside-related ototoxicity and presbycusis, which are known to be associated with production of free radicals.
AB - The double whole-cell patch-clamp configuration was applied to analyze gap junctional conductance (Gj) of isolated pairs of cochlear supporting Hensen cells of guinea pig under control conditions and in the presence of hydrogen peroxide (H2O2). Under control conditions, the dependence of Gj on transjunctional voltage (Vj) appeared to vary between different cell pairs with a maximum value of about 40 nS at Vj close to 0 mV. The voltage dependence and the maximum amplitude of Gj stayed constant for at least 2 hr. Addition of H2O2 to the bath at concentrations above 0.08 mm caused a significant decrease of Gj, but the membrane potential of about -30 mV was not affected. In parallel, intracellular free calcium ([Ca2+]i) was followed using fura-2. At 0.8 mm H2O2, a sustained increase of [Ca2+]i was observed, while 0.08 mm H2O2 evoked an oscillating-like behavior of [Ca2+]i. We propose that the H2O2-evoked inhibition of gap junctional coupling of Hensen cells is closely related to pathophysiological conditions such as noise- induced hearing loss, aminoglycoside-related ototoxicity and presbycusis, which are known to be associated with production of free radicals.
KW - Animals
KW - Calcium/metabolism
KW - Calcium Signaling/drug effects
KW - Cochlea/cytology
KW - Electric Conductivity
KW - Gap Junctions/drug effects
KW - Guinea Pigs
KW - Hydrogen Peroxide/pharmacology
KW - Intracellular Fluid/drug effects
KW - Patch-Clamp Techniques
U2 - 10.1007/s00232001-0014-4
DO - 10.1007/s00232001-0014-4
M3 - Article
C2 - 11420597
VL - 181
SP - 107
EP - 114
JO - The journal of membrane biology
JF - The journal of membrane biology
SN - 0022-2631
IS - 2
ER -