Találati lista | Tudóstér

001-es BibID:	BIBFORM053175
035-os BibID:	(Scopus)84887143836 (WoS)000326116400010
Első szerző:	Nagy Norbert (kísérletes farmakológus)
Cím:	[Ca2+]i-induced augmentation of the inward rectifier potassium current (IK1) in canine and human ventricular myocardium / Norbert Nagy, Károly Acsai, Anita Kormos, Zsuzsanna Sebők, Attila S. Farkas, Norbert Jost, Péter P. Nánási, Julius Gy. Papp, András Varró, András Tóth
Dátum:	2013
ISSN:	0031-6768
Megjegyzések:	The inward rectifier K? current (IK1) plays an important role in terminal repolarization and stabilization of the resting potential in cardiac cells. Although IK1 was shown to be sensitive to changes in intracellular Ca?? concentration ([Ca??]i), the nature of this Ca?? sensitivity-in spite of its deep influence on action potential morphology-is controversial. Therefore, we aimed to investigate the effects of a nonadrenergic rise in [Ca??]i on the amplitude of IK1 in canine and human ventricular myocardium and its consequences on cardiac repolarization. IK1, defined as the current inhibited by 10 ?M Ba??, was significantly increased in isolated canine myocytes following a steady rise in [Ca??]i. Enhanced IK1 was also observed when [Ca??]i was not buffered by ethylene glycol tetraacetic acid, and [Ca??]I transients were generated. This [Ca??]i-dependent augmentation of IK1 was largely attenuated after inhibition of CaMKII by 1 ?M KN-93. Elevation of [Ca??]o in multicellular canine and human ventricular preparations resulted in shortening of action potentials and acceleration of terminal repolarization. High [Ca??]o enhanced the action potential lengthening effect of the Ba(2+)-induced IK1 blockade and attenuated the prolongation of action potentials following a 0.3-?M dofetilide-induced IKr blockade. Blockade of IKs by 0.5 ?M HMR-1556 had no significant effect on APD90 in either 2 mM or 4 mM [Ca??]o. It is concluded that high [Ca??]i leads to augmentation of the Ba??-sensitive current in dogs and humans, regardless of the mechanism of the increase. This effect seems to be at least partially mediated by a CaMKII-dependent pathway and may provide an effective endogenous defense against cardiac arrhythmias induced by Ca?? overload.
Tárgyszavak:	Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Canine/human myocardium Inward rectifier K+ current (IK1) Cytosolic Ca2+ Action potential duration Ventricular repolarization Ba2+
Megjelenés:	Pflugers Archiv-European Journal of Physiology. - 465 : 11 (2013), p. 1621-1635. -
További szerzők:	Acsai Károly Kormos Anita Sebők Zsuzsanna Farkas Attila (1961-) (farmakológus) Jost Norbert Nánási Péter Pál (1956-) (élettanász) Papp Gy. Julius (Szeged) Varró András (1954-) (farmakológus, klinikai farmakológus) Tóth András (farmakológus)
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon: