CCL

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1.

001-es BibID:BIBFORM038801
035-os BibID:PMID:15950414
Első szerző:Borkó Rezső
Cím:Slow motility, electromotility and lateral wall stiffness in the isolated outer hair cells / Rezső Borkó, Tamás József Batta, István Sziklai
Dátum:2005
ISSN:0378-5955
Megjegyzések:Slow motile length changes of isolated, apical turn outer hair cells (OHCs) (n=36) were induced by perfusion of saline (flow rate: 0.6 microl/min) as a mechanical challenge or by perfusion of 12.5 mM KCl solution for 90 s as a chemical and mechanical challenge with and without ocadaic acid (OA), a serine/threonine protein phosphatase inhibitor. Electromotility was evoked by square pulses from +/-35 mV to +/-240 mV during the slow shortening and recovery period (n=36). Stiffness of the lateral wall was measured by the micropipette aspiration technique (n=20). Saline perfusion caused a reversible shortening of 774+/-87 nm (n=9) as well as K+ of 1465+/-159 nm (n=9). Slow shortening increased lateral wall stiffness (1.25+/-0.02 to 1.52+/-0.03 nN/microm) (n=5-5). Simultaneously, electromotility magnitude decreased (n=9). Ocadaic acid blocked slow shortening, increased lateral wall stiffness, and decreased the magnitude of electromotility. Mechanical or mechanical+chemical stimulation of ocadaic acid treated OHCs do not further change stiffness or electromotility. Isolated OHCs respond with slow shortening and consutive cell stiffness increase to mechanical insult. This phenomenon seems operating with calcium-, and phosphorylation-dependent modifications of the cytoskeletal proteins. The subsequent electromotility gain decrease suggests a slow OHC shortening driven regulation of the cochlear amplifier with simultaneous safety control of the auditory periphery against overstimulation.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
egyetemen (Magyarországon) készült közlemény
Megjelenés:Hearing Research. - 207 : 1-2 (2005), p. 68-75. -
További szerzők:Batta József Tamás (1970-) (fül-orr-gégész) Sziklai István (1954-) (fül-orr-gégész)
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Intézményi repozitóriumban (DEA) tárolt változat
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2.

001-es BibID:BIBFORM040490
Első szerző:Sziklai István (fül-orr-gégész)
Cím:Human otosclerotic bone-derived peptide decreases the gain of the electromotility in isolated outer hair cells / Istvan Sziklai
Dátum:1996
ISSN:0378-5955
Megjegyzések:An otosclerotic peptide (OP) (Sziklai et al., 1985a.b) was purified from perilymph and stapes footplate of otosclerotic patients by Sephadex G-25 gel column chromatography and subsequent isotachophoretic (ITP) separation. The transfer function of the electromotility was measured by inserting the isolated outer hair cells (OHC) into a partitioning microchamber (Evans et al., 1991) and applying a series of pairs of brief square-pulse stimuli with opposite polarity and with increasing magnitude. Somatic length changes of the inserted part of the OHCs were measured by an optoelectronic system. The isotachophoretically homogeneous peptide exerted a gain and magnitude decreasing effect on the transfer function of electromotility of isolated OHCs of the guinea pig, in vitro. The operating point of the electromotility did not change due to the effect of the peptide. The peptide decreased the electromotile performance within a minute and bath exchange to normal saline did not completely restore the transfer curve to baseline. Application of caffeine to the cells already under the effect of the otosclerotic peptide produced an opposite effect: gain and magnitude increase. Simultaneous application of acetylcholine (ACh) did not antagonize the effect of OP. The underlying mechanism of the action of OP on the transfer function of electromotility of OHCs is postulated to involve the modulation of intracellular Ca2- concentration.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
egyetemen (Magyarországon) készült közlemény
Megjelenés:Hearing Research. - 95 : 1-2 (1996), p. 100-107. -
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
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3.

001-es BibID:BIBFORM040491
035-os BibID:PMID:8793511
Első szerző:Sziklai István (fül-orr-gégész)
Cím:Effect of acetylcholine and GABA on the transfer function of electromotility in isolated outer hair cells / István Sziklai, David Z.Z. He, Peter Dallos
Dátum:1996
ISSN:0378-5955
Megjegyzések:Outer hair cells (OHC) from high- and low-frequency regions were separately isolated from guinea pig cochleas. The cells were inserted with their ciliary pole first into a partitioning microchamber so that only 20-50% of the cell length was excluded. Somatic length changes due to transcellular electrical stimulation were measured at the cuticular plate in the inserted portion of the cells. Transfer curves of electromotility of the OHCs were obtained by both a series of brief (2.5 ms) and longer (30 ms) square pulses with opposite polarity and linearly increasing size from 40 to 280 mV in both negative and positive directions. Alterations in the transient and steady-state electromotility transfer curves were examined by application of acetylcholine (ACh) and gamma-aminobutyric acid (GABA) to the synaptic pole. ACh, in the concentration range of 10-30 microM, evoked a significant magnitude and gain increase of electromotility in both transient and steady-state responses without a measurable shift in the operating point of the displacement-voltage transfer curve. A tonotopic response magnitude difference is found for ACh challenge. Basal turn OHCs responded with greater magnitude increase (+90% increase from control) than apical turn OHCs (+40%). GABA exerted an opposite effect, again in a location-dependent manner. Magnitude response decreased about 30% for long cells and 14% for short ones. Atropin, a muscarinic receptor antagonist, completely blocked the increase in electromotility response due to ACh. However, D-tubocurarine, a nicorinic receptor antagonist, while not blocking the ACh effect, altered the cell's apparent operating point. Bicuculline methiodide, a GABAA-receptor antagonist, completely arrested GABA influences on the electromotility response. These results suggest that both ACh and GABA can change the electromotile activity of OHCs, in a tonotopically biased manner. ACh challenge evokes greater magnitude responses in basal turn OHCs, whereas GABA induces greater motility response decrease in apical turn OHCs. The control of the gain and magnitude of electromotility by the transmitter substances appear to involve at least two mechanisms. One is probably related to conformational changes of the voltage-to-movement converter molecules and a change in their number in an effective operational pool, the other operates via changing the electrical resistance of the basolateral cell membrane.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
külföldön készült közlemény
Megjelenés:Hearing Research. - 95 : 1-2 (1996), p. 87-99. -
További szerzők:He, David Z. Z. Dallos Péter
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
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4.

001-es BibID:BIBFORM040609
Első szerző:Sziklai István (fül-orr-gégész)
Cím:Vasopressin entry into the inner ear fluids of the rat / I. Sziklai, E. Ferrary, O. Sterkers, C. Amiel
Dátum:1987
ISSN:0378-5955
Megjegyzések:The entry of arginine-vasopressin (AVP) and sucrose into cochlear endolymph, perilymph of scala vestibuli (PLV), perilymph of scala tympani (PLT), and cisternal cerebrospinal fluid (CSF) was studied, in anesthetized rats, after the administration into the cerebral lateral ventricle of a 10 microliter solution containing the radioactive tracers. Both tracers were detected in PLV, PLT, and CSF but not in endolymph. Monoexponential decay curves were calculated for PLV, PLT, and CSF, and for each tracer no difference was found between the regression lines calculated for the different fluids. These results indicate that (i) injection into the cerebral lateral ventricle is a useful tool to study the permeability of the cochlear epithelium to different solutes and (ii) no specific transport system exists for AVP across the cochlear epithelium, suggesting that AVP may exert its effect via the perilymphatic side of the stria vascularis.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Hearing Research. - 29 : 2-3 (1987), p. 245-250. -
További szerzők:Ferrary, Evelyne Sterkers, Olivier Amiel, Claude
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
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5.

001-es BibID:BIBFORM040765
Első szerző:Szőnyi Magdolna
Cím:Cyclic GMP and outer hair cell electromotility / Szönyi Magdolna, He David Z. Z., Ribári Ottó, Sziklai István, Dallos Peter
Dátum:1999
ISSN:0378-5955
Megjegyzések:The aim of this study is to examine the effect of phosphorylation pathways on the electrically evoked fast motile response of isolated outer hair cells (OHCs). Transcellular electrical stimulation was applied in the microchamber to guinea pig OHCs and motility was measured before and after drug application. Forskolin (adenylate cyclase activator), phorbol 12-myristate 13-acetate (PMA, protein kinase C activator) and dibutyryl 3',5'-cyclic guanosine monophosphate (cGMP agonist) were studied. As controls, L15 medium and dimethyl-sulfoxide (DMSO) were used. In each group, 12 cells were measured. Forskolin and PMA were dissolved in 0.1% DMSO to render them membrane permeable. DMSO by itself caused a statistically significant electromotility magnitude decrease. Forskolin and PMA could not reverse the motility decrease due to DMSO, the effects seen in their presence were the same as observed with DMSO alone. Thus, neither 3',5'-cyclic AMP-dependent protein kinase nor calcium/phospholipid-dependent protein kinase appear to have modulatory effects on electromotility. Dibutyryl cGMP (DBcGMP), in concentrations of 200 microM, elicited a significant electromotility magnitude increase. The DBcGMP effect could be inhibited by co-application of 200 microM DBcGMP and 100 microM 8-Rp-pCPT-cGMPS (8-4-chlorophenylthio-guanosine 3',5'-cyclic monophosphothioate, Rp isomer, a cGMP antagonist). Our results suggest that OHC electromotility is modulated by a cGMP-dependent pathway.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Hearing Research. - 137 : 1-2 (1999), p. 29-42. -
További szerzők:He, David Z. Z. Ribári Ottó (1932-) (fül-orr-gégész, audiológus) Sziklai István (1954-) (fül-orr-gégész) Dallos Péter
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DOI
Intézményi repozitóriumban (DEA) tárolt változat
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6.

001-es BibID:BIBFORM004847
Első szerző:Szűcs Attila (fül-orr-gégész)
Cím:Differential expression of purinergic receptor subtypes in the outer hair cells of the guinea pig / Attila Szücs, Henrietta Szappanos, Andrea Tóth, Zsolt Farkas, György Panyi, László Csernoch, István Sziklai
Dátum:2004
Megjegyzések:ATP acts as a neuro-modulator through purinoceptors in many different tissues. Many subtypes of these receptors have been identified in the inner ear, but so far only two types have been shown to be present in the membrane of the isolated outer hair cells (OHCs). The aim of this study was to detect and visualize the existence and distribution of purinoceptor subtypes as well as to study the [Ca(2+)](i) response of these cells in response to stimulation with ATP. Four P2X and three P2Y receptor subtypes were identified with different expression pattern in the membrane of guinea pig outer hair cells. Whereas intense labeling was observed for P2X1, P2X2, P2X4, P2Y1, P2Y2, and P2Y4, the labeling for the subtype P2X7 was weak. There was a marked difference in the distribution of the receptors along the surface of the cells with a homogenous distribution in cases of P2X1, P2X4, and P2Y1. In contrast, P2X2 and P2Y2 receptor density was high mainly at the apical, while P2X7 and P2Y4 at the basal pole of the cells. Similarly a heterogeneity was observed in the ATP-induced transient elevation in [Ca(2+)](i), which had either fast kinetics without desensitization or slow rise with desensitization.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Animals
Calcium
Cells
Female
Guinea Pigs
Hair Cells,Outer
Hungary
Immunohistochemistry
Kinetics
Male
metabolism
Microscopy, Fluorescence
Receptors, Purinergic P2
Research
Support
Tissue Distribution
Megjelenés:Hearing Research. - 196 : 1-2 (2004), p. 2-7. -
További szerzők:Szappanos Henrietta (1976-) (biológus, élettanász) Tóth Andrea (1973-) (fül-orr-gégész) Farkas Zsolt (1969-) (fül-orr-gégész) Panyi György (1966-) (biofizikus) Csernoch László (1961-) (élettanász) Sziklai István (1954-) (fül-orr-gégész)
Internet cím:elektronikus változat
DOI
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