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001-es BibID:BIBFORM030250
035-os BibID:WOS:000182475600002
Első szerző:Fülöp László (kardiológus)
Cím:Differences in electrophysiological and contractile properties of mammalian cardiac tissues bathed in bicarbonate - and HEPES-buffered solutions / L. Fülöp, G. Szigeti, J. Magyar, N. Szentandrássy, T. Ivanics, Z. Miklós, L. Ligeti, A. Kovács, G. Szénási, L. Csernoch, P. P. Nánási, T. Bányász
Megjegyzések:Aim: The aim of this study was to compare the action potential configuration, contractility, intracellular Ca2+ and H+ concentrations in mammalian cardiac tissues bathed with Krebs and Tyrode solutions at 37 degreesC. Results: In Langendorff-perfused guinea-pig hearts, loaded with the fluorescent Ca2+ -indicator Fura-2, or H+ -sensitive dye carboxy-SNARF, shifts from Krebs to Tyrode solution caused intra-cellular acidification, increased diastolic pressure and [Ca2+ ](i) , decreased systolic pressure and [Ca2+ ](i) , leading to a reduction in the amplitude of [Ca2+ ](i) transients and pulse pressure. Contractility was also depressed in canine ventricular trabeculae when transferred from Krebs to Tyrode solution. Shifts from Krebs to Tyrode solution increased the duration of action potentials in multicellular cardiac preparations excised from canine and rabbit hearts but not in isolated cardiomyocytes. All these changes in action potential morphology, contractility, [Ca2+ ](i) and [H+ ](i) were readily reversible by addition of 26 mmol L-1 bicarbonate to Tyrode solution. Effects of dofetilide and CsCl, both blockers of the delayed rectifier K current, on action potential duration were compared in Krebs and Tyrode solutions. Dofetilide lengthened rabbit ventricular action potentials in a significantly greater extent in Tyrode than in Krebs solution. Exposure of canine Purkinje fibres to CsCl evoked early after depolarizations within 40 min in all preparations incubated with Tyrode solution, but not in those bathed with Krebs solution. Conclusion: It is concluded that the marked differences in action potential morphology, [Ca2+ ](i) , [H+ ](i) and contractility observed between preparations bathed with Krebs and Tyrode solutions are more likely attributable to differences in the intracellular buffering capacities of the two media.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
egyetemen (Magyarországon) készült közlemény
Megjelenés:Acta Physiologica Scandinavica. - 178 : 1 (2003), p. 11-18. -
További szerzők:Szigeti Gyula (1969-) (élettanász, elektrofiziológus) Magyar János (1961-) (élettanász) Szentandrássy Norbert (1976-) (élettanász) Ivanics Tamás Miklós Zsuzsanna Ligeti László Kovács A. Szénási Gábor Csernoch László (1961-) (élettanász) Nánási Péter Pál (1956-) (élettanász) Bányász Tamás (1960-) (élettanász)
Internet cím:DOI
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001-es BibID:BIBFORM001043
Első szerző:Gönczi Mónika (élettanász)
Cím:Hypotonic stress influence the membrane potential and alter the proliferation of keratinocytes in vitro / Gönczi M., Szentandrássy N., Fülöp L., Telek A., Szigeti G. P., Magyar J., Bíró T., Nánási P. P., Csernoch L.
ISSN:0906-6705 (Print)
Megjegyzések:Keratinocyte proliferation and differentiation is strongly influenced by mechanical forces. We investigated the effect of osmotic changes in the development of HaCaT cells in culture using intracellular calcium measurements, electrophysiological recordings and molecular biology techniques. The application of hypotonic stress (174 mOsmol/l) caused a sustained hyperpolarization of HaCaT cells from a resting potential of -27 +/- 4 to -51 +/- 9 mV. This change was partially reversible. The surface membrane channels involved in the hyperpolarization were identified as chloride channels due to the lack of response in the absence of the anion. Cells responded with an elevation of intracellular calcium concentration to hypotonic stress, which critically depended on external calcium. The presence of phorbol-12-myristate-13-acetate in the culture medium for 12 h augmented the subsequent response to hypotonic stress. A sudden switch from iso- to hypotonic solution increased cell proliferation and suppressed the production of involucrin, filaggrin and transglutaminase, markers of keratinocyte differentiation. It is concluded that sudden mechanical forces increase the proliferation of keratinocytes through alterations in their membrane potential and intracellular calcium concentration. These changes together with additional modifications in channel expression and intracellular signalling mechanisms could underlie the increased proliferation of keratinocytes in hyperproliferative skin diseases.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Experimental Dermatology. - 16 (2007), p. 302-310. -
További szerzők:Szentandrássy Norbert (1976-) (élettanász) Fülöp László (1976-) (kardiológus) Telek Andrea (1977-) (élettanász) Szigeti Gyula (1969-) (élettanász, elektrofiziológus) Magyar János (1961-) (élettanász) Bíró Tamás (1968-) (élettanász) Nánási Péter Pál (1956-) (élettanász) Csernoch László (1961-) (élettanász)
Internet cím:elektronikus változat
elektronikus változat
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