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001-es BibID:	BIBFORM004074
Első szerző:	Birinyi Péter (élettanász)
Cím:	The Na+/Ca2+ exchange blocker SEA0400 fails to enhance cytosolic Ca2+ transient and contractility in canine ventricular cardiomyocytes / Birinyi P., Tóth A., Jóna I., Acsai K., Almássy J., Nagy N., Prorok J., Gherasim I., Papp Z., Hertelendi Z., Szentandrássy N., Bányász T., Fülöp F., Papp J. G., Varró A., Nánási P. P., Magyar J.
Dátum:	2008
Megjegyzések:	Aims This study was designed to evaluate the effects of the Na+/Ca2+ exchange (NCX) inhibitor SEA0400 on Ca2+ handling in isolated canine ventricular myocytes. Methods and results Intracellular Ca2+ ([Ca2+](i)) transients, induced by either field stimulation or caffeine flush, were monitored using Ca2+ indicator dyes. [Ca2+](i)-dependent modulation of the inhibitory effect of SEA0400 on NCX was characterized by the changes in Ni2+-sensitive current in voltage-clamped myocytes. Sarcoplasmic reticulum (SR) Ca2+ release and uptake were studied in SIR membrane vesicles. Gating properties of single-ryanodine receptors were analysed in lipid bilayers. Ca2+ sensitivity of the contractile machinery was evaluated in chemically skinned myocytes. In myocytes paced at 1 Hz, neither diastolic [Ca2+](i) nor the amplitude of [Ca2+](i) transients was significantly altered by SEA0400 up to the concentration of 1 mu M, which was shown to inhibit the exchange current. The blocking effect of SEA0400 on NCX decreased with increasing [Ca2+](i), and it was more pronounced in reverse than in forward mode operation at every [Ca2+](i) examined. The rate of decay of the caffeine-induced [Ca2+](i) transients was decreased significantly by 1 mu M SEA0400; however, this effect was only a fraction of that observed with 10 mM NiCl2. Neither SR Ca2+ release and uptake nor cell shortening and Ca2+ sensitivity of the contractile proteins were influenced by SEA0400. Conclusion The lack of any major SEA0400-induced shift in Ca2+ transients or contractility of myocytes can well be explained by its limited inhibitory effect on NCX (further attenuated by elevated [Ca2+](i) levels) and a concomitant reduction in Ca2+ influx due to the predominantly reverse mode blockade of NCX and suppression of L-type Ca2+ current.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Cardiovascular Research. - 78 : 3 (2008), p. 476-484. -
További szerzők:	Tóth András (farmakológus) Jóna István (1948-) (élettanász, fizikus) Acsai Károly Almássy János (1981-) (élettanász, biológus, angol-magyar szakfordító) Nagy Norbert (1977-) (kísérletes farmakológus) Prorok János Gherasim, Iuliana Papp Zoltán (1965-) (kardiológus, élettanász) Hertelendi Zita (1978-) (orvos) Szentandrássy Norbert (1976-) (élettanász) Bányász Tamás (1960-) (élettanász) Fülöp Ferenc Papp Gy. Julius (Szeged) Varró András (1954-) (farmakológus, klinikai farmakológus) Nánási Péter Pál (1956-) (élettanász) Magyar János (1961-) (élettanász)
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001-es BibID:	BIBFORM083023
035-os BibID:	(WoS)000522138400002 (Scopus)85078193947 (PubMed)31958464
Első szerző:	Horváth Balázs (élettanász)
Cím:	Late sodium current in human, canine and guinea pig ventricular myocardium / Balázs Horváth, Tamás Hézső, Norbert Szentandrássy, Kornél Kistamás, Tamás Árpádffy-Lovas, Richárd Varga, Péter Gazdag, Roland Veress, Csaba Dienes, Dóra Baranyai, János Almássy, László Virág, Norbert Nagy, István Baczkó, János Magyar, Tamás Bányász, András Varró, Péter P. Nánási
Dátum:	2020
ISSN:	0022-2828
Megjegyzések:	Although late sodium current (INa-late) has long been known to contribute to plateau formation of mammalian cardiac action potentials, lately it was considered as possible target for antiarrhythmic drugs. However, many aspects of this current are still poorly understood. The present work was designed to study the true profile of INa-late in canine and guinea pig ventricular cells and compare them to INa-late recorded in undiseased human hearts. INa-late was defined as a tetrodotoxin-sensitive current, recorded under action potential voltage clamp conditions using either canonic- or self-action potentials as command signals. Under action potential voltage clamp conditions the amplitude of canine and human INa-late monotonically decreased during the plateau (decrescendo-profile), in contrast to guinea pig, where its amplitude increased during the plateau (crescendo profile). The decrescendo-profile of canine INa-late could not be converted to a crescendo-morphology by application of ramp-like command voltages or command action potentials recorded from guinea pig cells. Conventional voltage clamp experiments revealed that the crescendo INa-late profile in guinea pig was due to the slower decay of INa-late in this species. When action potentials were recorded from multicellular ventricular preparations with sharp microelectrode, action potentials were shortened by tetrodotoxin, which effect was the largest in human, while smaller in canine, and the smallest in guinea pig preparations. It is concluded that important interspecies differences exist in the behavior of INa-late. At present canine myocytes seem to represent the best model of human ventricular cells regarding the properties of INa-late. These results should be taken into account when pharmacological studies with INa-late are interpreted and extrapolated to human. Accordingly, canine ventricular tissues or myocytes are suggested for pharmacological studies with INa-late inhibitors or modifiers. Incorporation of present data to human action potential models may yield a better understanding of the role of INa-late in action potential morphology, arrhythmogenesis, and intracellular calcium dynamics.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Late Na+ current Ventricular repolarization Action potential voltage clamp Dog myocytes Human myocytes
Megjelenés:	Journal of Molecular and Cellular Cardiology. - 139 (2020), p. 14-23. -
További szerzők:	Hézső Tamás (1993-) (élettanász) Szentandrássy Norbert (1976-) (élettanász) Kistamás Kornél (1986-) (biológus) Árpádffy-Lovas Tamás Varga Richárd Gazdag Péter Veress Roland (1992-) (molekuláris biológus) Dienes Csaba (1995-) (gyógyszerész) Baranyai Dóra Almássy János (1981-) (élettanász, biológus, angol-magyar szakfordító) Virág László (élettanász Szeged) Nagy Norbert (1977-) (kísérletes farmakológus) Baczkó István Magyar János (1961-) (élettanász) Bányász Tamás (1960-) (élettanász) Varró András (1954-) (farmakológus, klinikai farmakológus) Nánási Péter Pál (1956-) (élettanász)
Pályázati támogatás:	GINOP-2.3.2.-15-2016-00040 GINOP EFOP-3.6.2-16-2017-00006 EFOP ÚNKP-19-4 Egyéb ÚNKP-19-2 Egyéb NKFIH-K115397 NKFIH NKFIH-PD120794 NKFIH NKFIH-FK128116 NKFIH
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