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001-es BibID:BIBFORM037346
Első szerző:Szentandrássy Norbert (élettanász)
Cím:Role of action potential configuration and the contribution of Ca2+ and K+ currents to isoprenaline-induced changes in canine ventricular cells / N. Szentandrássy, V. Farkas, L. Bárándi, B. Hegyi, F. Ruzsnavszky, B. Horváth, T. Bányász, J. Magyar, I. Márton, P. P. Nánási
Dátum:2012
ISSN:0007-1188
Megjegyzések:BACKGROUND AND PURPOSE: Although isoprenaline (ISO) is known to activate several ion currents in mammalian myocardium, little is known about the role of action potential morphology in the ISO-induced changes in ion currents. Therefore, the effects of ISO on action potential configuration, L-type Ca2+ current (ICa), slow delayed rectifier K+ current (IKs) and fast delayed rectifier K+ current (IKr)were studied and compared in a frequency-dependent manner using canine isolated ventricular myocytes from varioustransmural locations.EXPERIMENTAL APPROACHAction potentials were recorded with conventional sharp microelectrodes; ion currents were measured using conventional and action potential voltage clamp techniques.KEY RESULTSIn myocytes displaying a spike-and-dome action potential configuration (epicardial and midmyocardial cells), ISO caused reversible shortening of action potentials accompanied by elevation of the plateau. ISO-induced action potential shortening was absent in endocardial cells and in myocytes pretreated with 4-aminopyridine. Application of the IKr blocker E-4031 failed to modify the ISO effect, while action potentials were lengthened by ISO in the presence of the IKs blocker HMR-1556. Bothaction potential shortening and elevation of the plateau were prevented by pretreatment with the ICa blocker nisoldipine.Action potential voltage clamp experiments revealed a prominent slowly inactivating ICa followed by a rise in IKs, both currents increased with increasing the cycle length.CONCLUSIONS AND IMPLICATIONSThe effect of ISO in canine ventricular cells depends critically on action potential configuration, and the ISO-induced activation of IKs ? but not IKr ? may be responsible for the observed shortening of action potentials
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
heart
action potential
calcium current
potassium current
Megjelenés:British Journal of Pharmacology. - 167 : 3 (2012), p. 599-611. -
További szerzők:Farkas Viktória Bárándi László (1984-) (élettanász) Hegyi Bence (1987-) (élettanász) Ruzsnavszky Ferenc (1984-) (élettanász) Horváth Balázs (1981-) (élettanász) Bányász Tamás (1960-) (élettanász) Magyar János (1961-) (élettanász) Márton Ildikó (1954-) (fogszakorvos) Nánási Péter Pál (1956-) (élettanász)
Pályázati támogatás:TÁMOP-4.2.1/B-09/1/KONV-2010-0007
TÁMOP
A feszültségfüggő K-csatornák szerepe excitábilis sejtekben
Internet cím:DOI
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