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1.

001-es BibID:BIBFORM067778
Első szerző:Acsai Károly
Cím:Role of the dysfunctional ryanodine receptor - Na+ -Ca2+ exchanger axis in progression of cardiovascular diseases : what we can learn from pharmacological studies? / Acsai K., Ördög B., Varró A., Nánási P. P.
Dátum:2016
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:European Journal of Pharmacology 779 (2016), p. 91-101. -
További szerzők:Ördög Balázs Varró András (1954-) (farmakológus, klinikai farmakológus) Nánási Péter Pál (1956-) (élettanász)
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2.

001-es BibID:BIBFORM001042
Első szerző:Acsai Károly
Cím:Effect of partial blockade of the Na+/Ca2+ - exchanger on Ca2+ handling in isolated rat ventricular myocytes / Károly Acsai, Attila Kun, Attila S. Farkas, Ferenc Fülöp, Norbert Nagy, Marianna Balázs, Norbert Szentandrássy, Péter P. Nánási, Julius Gy. Papp, András Varró, András Tóth
Dátum:2007
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:European Journal of Pharmacology. - 576 : 1-3 (2007), p. 1-6. -
További szerzők:Kun Attila Farkas S. Attila Fülöp Ferenc Nagy Norbert (1977-) (kísérletes farmakológus) Balázs Marianna Szentandrássy Norbert (1976-) (élettanász) Nánási Péter Pál (1956-) (élettanász) Papp Gy. Julius (Szeged) Varró András (1954-) (farmakológus, klinikai farmakológus) Tóth András (farmakológus)
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3.

001-es BibID:BIBFORM037025
Első szerző:Bányász Tamás (élettanász)
Cím:Reverse rate dependency is an intrinsic property of canine cardiac preparations / Banyasz Tamas, Horvath Balazs, Virag Laszlo, Barandi Laszlo, Szentandrassy Norbert, Harmati Gabor, Magyar Janos, Marangoni Stefano, Zaza Antonio, Varro Andras, Nanasi Peter P.
Dátum:2009
ISSN:0008-6363
Megjegyzések:Class III antiarrhythmic agents exhibit reverse rate-dependent lengthening of the action potential duration (APD). In spite of the several theories developed so far to explain this reverse rate dependency (RRD), its mechanism has not yet been clarified. The aim of the present work was to further elucidate the mechanisms responsible for reverse rate-dependent drug effects. Methods and resultsAction potentials were recorded from multicellular canine ventricular preparations and isolated cardiomyocytes, at cycle lengths (CLs) varying from 0.3 to 5 s, using conventional sharp microelectrodes. APD was either modified by applying inward and outward current pulses, or by superfusion of agents known to lengthen and shorten APD. Net membrane current (Im) was calculated from action potential waveforms. The hypothesis that RRD may be implicit in the relationship between Im and APD was tested by numerical modelling. Both drug-induced lengthening (by veratrine, BAY-K 8644, dofetilide, and BaCl2) and shortening (by lidocaine and nicorandil) of action potentials displayed RRD, i.e. changes in APD were greater at longer than at shorter CL. A similar dependency of effect on CL was found when repolarization was modified by injection of inward or outward current pulses. Im measured at various points during repolarization was inversely proportional to APD and to CL. Model simulations showed that RRD is expected as a consequence of the non-linearity of the relationship between Im and APD. ConclusionRRD of APD modulation is shared, although with differences in magnitude, by interventions of very different nature. RRD can be interpreted as a consequence of the relationship between Im and APD and, as such, is expected in all species having positive APD-CL relationship. This implies that the development of agents prolonging APD with direct rate dependency, or even completely devoid of RRD, may be difficult to achieve.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
egyetemen (Magyarországon) készült közlemény
Megjelenés:Cardiovascular Research. - 84 : 2 (2009), p. 237-244. -
További szerzők:Horváth Balázs (1981-) (élettanász) Virág László (élettanász Szeged) Bárándi László (1984-) (élettanász) Szentandrássy Norbert (1976-) (élettanász) Harmati Gábor (1983-) (élettanász) Magyar János (1961-) (élettanász) Marangoni, Stefano Zaza, Antonio Varró András (1954-) (farmakológus, klinikai farmakológus) Nánási Péter Pál (1956-) (élettanász)
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4.

001-es BibID:BIBFORM032954
Első szerző:Bányász Tamás (élettanász)
Cím:Frequency-dependent characteristics of human cardiac muscle / Tamás Bányász, János Magyar, Péter Szigligeti, Csaba Pankucsi, András Varró, Péter P. Nánási
Dátum:1997
Megjegyzések:OBJECTIVES: To characterize the steady state frequency-dependent properties and restitution kinetics of action potential duration (APD) in isolated human atrial and ventricular cardiac muscle preparations. MATERIALS AND METHODS: Conventional microelectrode techniques were used to record action potentials in preparations of human left ventricular muscle and right atrial appendages under steady state conditions or after abrupt changes in cycle length, ie, following increasingly longer diastolic intervals (DI). Restitution relations were generated by plotting APD against the respective DI. Restitution relations were fitted to multiexponential functions. RESULTS: Restitution of APD at 90% repolarization in ventricular preparations, paced at a basic cycle length (BCL) of 750 ms, were fitted as the sum of four exponentials, having time constants of 42.8 ms, 139 ms, 1.34 s and 16 s. Similar results were obtained for restitution of values of APD at 50% repolarization. In atrial preparations, restitution kinetics were characterized by three exponentials with time constants of 154 ms, 1.52 s and 25.5 s (BCL of 750 ms). The very fast component of restitution, observed in ventricular muscle, was apparently missing in atrial fibres. When atrial preparations were paced at a longer BCL of 5000 ms, no change in time constants of restitution was observed; however, the amplitudes of the second and third atrial components decreased significantly compared with preparations paced at a BCL of 750 ms. CONCLUSIONS: Comparing the time constant values estimated for restitution with the reported kinetic parameters of cardiac ion channels, it may be speculated that the first component of restitution in ventricular muscle is attributed to the recovery of L-type calcium current from inactivation. The lack of this very rapid component in atrial muscle can be explained by the parallel recovery of the calcium current and the transient outward potassium current, prominent in atrial myocardium. The second ventricular component (first in atrium) may be due to the time-dependent deactivation of the delayed rectifier potassium current. The third and fourth ventricular components (second and third components, respectively, in the atrium) are probably related to transient changes in intracellular ionic composition.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
egyetemen (Magyarországon) készült közlemény
Megjelenés:Experimental And Clinical Cardiology 2 : 3 (1997), p. 205-209. -
További szerzők:Magyar János (1961-) (élettanász) Szigligeti Péter Pankucsi Csaba (farmakológus) Varró András (1954-) (farmakológus, klinikai farmakológus) Nánási Péter Pál (1956-) (élettanász)
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5.

001-es BibID:BIBFORM030274
035-os BibID:WOS:000079560700007
Első szerző:Bányász Tamás (élettanász)
Cím:EGIS-7229, the new combined class III antiarrhythmic agent : lack of EAD inducing effect / Tamás Bányász, János Magyar, András Varró, Anikó Kovács, Ildikó Gyönös, Gábor Szénási, Péter P. Nánási
Dátum:1999
ISSN:0306-3623
Megjegyzések:EGIS-7229 is a novel antiarrhythmic candidate having multiple mechanisms of action with class III predominance. In this study, the effects of EGIS-7229 and sotalol on action potential duration (APD) and incidence of early afterdepolarizations (EADs) were studied and compared in rabbit papillary muscle by using conventional microelectrode techniques. In control bathing solution, both drugs increased APD in a concentration-dependent manner; however, the prolongation of APD was greater with sotalol than with EGIS-7229 when the same drug concentrations were compared. EAD developed in 3 of the 11 preparations (27%) bathed with a solution containing 3.6 mmol/l CsCl + 2 mmol/l KCl within the first 120 min of superfusion. The addition of 100 mu mol/l sotalol to this superfusate increased the incidence of EAD to 83% (10 from 12), whereas the addition of the same concentration of EGIS-7229 prevented the development of EAD in all of the 9 preparations studied. These differences in incidence of EAD are likely attributable to differences in drug-induced increases of APD-50 in the presence of CsCl. Prolongation of APD-90 showed less correlation with incidence of EAD than changes in APD-50. On the basis of these in vitro results, high concentrations of EGIS-7229 cannot be expected to be torsadogenic in vivo-in contrast with sotalol-presumably owing to the combined class III + IV activity of the compound. (C) 1999 Elsevier Science Inc. All rights reserved.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
egyetemen (Magyarországon) készült közlemény
Megjelenés:General Pharmacology. - 32 : 3 (1999), p. 329-333. -
További szerzők:Magyar János (1961-) (élettanász) Varró András (1954-) (farmakológus, klinikai farmakológus) Kovács Anikó Gyönös Ildikó Szénási Gábor Nánási Péter Pál (1956-) (élettanász)
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6.

001-es BibID:BIBFORM030251
035-os BibID:WOS:000182446700007
Első szerző:Bányász Tamás (élettanász)
Cím:Endocardial versus epicardial differences in L-type calcium current in canine ventricular myocytes studied by action potential voltage clamp / Tamás Bányász, László Fülöp, János Magyar, Norbert Szentandrássy, András Varró, Péter P. Nánási
Dátum:2003
ISSN:0008-6363
Megjegyzések:Objectives: The aim of the present study was to assess and compare the dynamics of L-type Ca2+ current (I-Ca.L) during physiologic action potential (AP) in canine ventricular cardiomyocytes of epicardial (EPI) and endocardial (ENDO) origin. Methods: I-Ca.L was recorded on cells derived from the two regions of the heart using both AP voltage clamp and conventional whole cell voltage clamp techniques. Results: AP voltage clamp experiments revealed that the decay of I-Ca.L is monotonic during endocardial AP, whereas the current is double-peaked (displaying a second rise) during epicardial AP. The amplitude of the first peak was significantly greater in ENDO (-4.6+/-0.8 pA/pF) than in EPI cells (-2.8+/-0.3 pA/pF). Application of epicardial APs as command pulses to endocardial cells yielded double-peaked I-Ca.L profiles, and increased the net charge entry carried by I-Ca.L during the AP from 0.187+/-0.059 to 0.262+/-0.056 pC/pF (n=5, P<0.05). No differences were observed in current densities and inactivation kinetics of I-Ca.L between EPI and ENDO cells when studied under conventional voltage clamp conditions. Nisoldipine shortened action potentials and eliminated the dome of the epicardial AP. Conclusion: I-Ca.L was shown to partially inactivate before and deactivate during phase-1 repolarization and reopening of these channels is responsible for the formation of the dome in canine EPI cells. The transmural differences in the profile of I-Ca.L could be well explained with differences in AP configuration. (C) 2003 European Society of Cardiology. Published by Elsevier Science B.V. All rights reserved.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
egyetemen (Magyarországon) készült közlemény
Megjelenés:Cardiovascular Research. - 58 : 1 (2003), p. 66-75. -
További szerzők:Fülöp László (1976-) (kardiológus) Magyar János (1961-) (élettanász) Szentandrássy Norbert (1976-) (élettanász) Varró András (1954-) (farmakológus, klinikai farmakológus) Nánási Péter Pál (1956-) (élettanász)
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7.

001-es BibID:BIBFORM024502
035-os BibID:(WoS)000294414700002 (Scopus)80052005781
Első szerző:Bányász Tamás (élettanász)
Cím:Mechanism of reverse rate-dependent action of cardioactive agents / Tamás Bányász, László Bárándi, Gábor Harmati, László Virág, Norbert Szentandrássy, Ildikó Márton, Antonio Zaza, András Varró, Péter P. Nánási
Dátum:2011
ISSN:0929-8673 1875-533X
Megjegyzések:Class 3 antiarrhythmic agents exhibit reverse rate-dependent lengthening of the action potential duration (APD), i.e. changes in APD are greater at longer than at shorter cycle lengths. In spite of the several theories developed to explain this reverse rate-dependency, its mechanism has been clarified only recently. The aim of the present study is to elucidate the mechanisms responsible for reverse rate-dependency in mammalian ventricular myocardium. Action potentials were recorded using conventional sharp microelectrodes from human, canine, rabbit, guinea pig, and rat ventricular myocardium in a rate-dependent manner. Rate-dependent drug-effects of various origin were studied using agents known to lengthen or shorten action potentials allowing thus to determine the drug-induced changes in APD as a function of the cycle length. Both drug-induced lengthening and shortening of action potentials displayed reverse rate-dependency in human, canine, and guinea pig preparations, but not in rabbit and rat myocardium. Similar results were obtained when repolarization was modified by injection of inward or outward current pulses in isolated canine cardiomyocytes. In contrast to reverse rate-dependence, drug-induced changes in APD well correlated with baseline APD values (i.e. that measured before the superfusion of drug or injection of current) in all of the preparations studied. Since the net membrane current (I(net)), determined from the action potential waveform at the middle of the plateau, was inversely proportional to APD, and consequently to cycle length, it is concluded that that reverse rate-dependency may simply reflect the inverse relationship linking I(net) to APD. In summary, reverse rate-dependency is an intrinsic property of drug action in the hearts of species showing positive APD - cycle length relationship, including humans. This implies that development of a pure K(+) channel blocking agent without reverse rate-dependent effects is not likely to be successful.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
antiarrhythmiás szerek
APD
Molekuláris Medicina
egyetemen (Magyarországon) készült közlemény
Megjelenés:Current medicinal chemistry. - 18 : 24 (2011), p. 3597-3606. -
További szerzők:Bárándi László (1984-) (élettanász) Harmati Gábor (1983-) (élettanász) Virág László (élettanász Szeged) Szentandrássy Norbert (1976-) (élettanász) Márton Ildikó (1954-) (fogszakorvos) Zaza, Antonio Varró András (1954-) (farmakológus, klinikai farmakológus) 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
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8.

001-es BibID:BIBFORM016887
Első szerző:Bárándi László (élettanász)
Cím:Drug-induced changes in action potential duration are proportional to action potential duration in rat ventricular myocardium / Bárándi, L., Harmati, G., Horváth, B., Szentandrássy, N., Magyar, J., Varró, A., Nánási, P.P., Bányász, T.
Dátum:2010
ISSN:0231-5882
Megjegyzések:Several cardioactive agents exhibit direct or reverse rate-dependent effects on action potential duration (APD) depending on the experimental conditions. Recently, a new theory has been proposed, suggesting that the reverse rate-dependent mode of drug-action may be a common property of canine, rabbit, guinea pig and human cardiac tissues, and this phenomenon is based on the dependence of drug-action on baseline APD. The aim of the present work was to examine the limitations of this hypothesis by studying the APD lengthening effect of K+ channel blockers and the APD shortening effect of Ca2+ channel blockers during the electrical restitution process of rat ventricular action potentials. Rat ventricular muscle was chosen because it has a set of ion currents markedly different from those of other species, its APD is shorter by one order of magnitude than that of the "plateau-forming" larger mammals, and most importantly, its APD increases at higher heart rates ? opposite to many other species. The restitution of APD was studied as a function of the diastolic interval, a parameter indicating the proximity of action potentials. It was found that drug-induced APD changes in rat myocardium are proportional with the pre-drug value of APD but not with the diastolic interval, indicating that not the proximity of consecutive action potentials, but the baseline APD itself may determine the magnitude of drug-induced APD changes.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Action potential duration
Electrical restitution
Membrane current
Reverse rate dependence
Ventricular repolarization
Megjelenés:General Physiology And Biophysics. - 29 : 3 (2010), p. 309-313. -
További szerzők:Harmati Gábor (1983-) (élettanász) Horváth Balázs (1981-) (élettanász) Szentandrássy Norbert (1976-) (élettanász) Magyar János (1961-) (élettanász) Varró András (1954-) (farmakológus, klinikai farmakológus) Nánási Péter Pál (1956-) (élettanász) Bányász Tamás (1960-) (élettanász)
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Borító:

9.

001-es BibID:BIBFORM016600
Első szerző:Bárándi László (élettanász)
Cím:Reverse rate-dependent changes are determined by baseline action potential duration in mammalian and human ventricular preparations / Bárándi László, Virág László, Jost Norbert, Horváth Zoltán, Koncz István, Papp Rita, Harmati Gábor, Horváth Balázs, Szentandrássy Norbert, Bányász Tamás, Magyar János, Zaza Antonio, Varró András, Nánási Péter P.
Dátum:2010
ISSN:0300-8428
Megjegyzések:Class III antiarrhythmic agents exhibit reverse rate-dependent lengthening of the action potential duration (APD). In spite of the several theories developed so far to explain this reverse rate-dependency (RRD), its mechanism has not yet been clarified. The aim of the present work was to further elucidate the mechanisms responsible for RRD in mammalian ventricular myocardium. Action potentials were recorded using conventional sharp microelectrodes from human, canine, rabbit and guinea pig ventricular myocardium in a rate-dependent manner varying the cycle length (CL) between 0.3 and 5 s. Rate-dependent drug effects were studied using agents known to lengthen or shorten action potentials, and these drug-induced changes in APD were correlated with baseline APD values. Both drug-induced lengthening (by dofetilide, sotalol, E-4031, BaCl2, veratrine, BAY K 8644) and shortening (by mexiletine, tetrodotoxin, lemakalim) of action potentials displayed RRD, i.e., changes in APD were greater at longer than at shorter CLs. In rabbit, where APD is a biphasic function of CL, the drug-induced APD changes were proportional to baseline APD values but not to CL. Similar results were obtained when repolarization was modified by injection of inward or outward current pulses in isolated canine cardiomyocytes. In each case the change in APD was proportional to baseline APD (i.e., that measured before the superfusion of drug or injection of current). Also, the net membrane current (Inet), determined from the action potential waveform at the middle of the plateau, was inversely proportional to APD and consequently with to CL. The results indicate that RRD is a common characteristic of all the drugs tested regardless of the modified ion current species. Thus, drug-induced RRD can be considered as an intrinsic property of cardiac membranes based on the inverse relationship between Inet and APD.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Ventricular repolarization
Action potential duration
Reverse rate dependence
Membrane current
Human myocardium
Mammalian cardiac cells
egyetemen (Magyarországon) készült közlemény
Megjelenés:Basic Research In Cardiology. - 105 : 3 (2010), p. 315-323. -
További szerzők:Virág László (élettanász Szeged) Jost Norbert Horváth Zoltán Koncz István (Szeged) Papp Rita Harmati Gábor (1983-) (élettanász) Horváth Balázs (1981-) (élettanász) Szentandrássy Norbert (1976-) (élettanász) Bányász Tamás (1960-) (élettanász) Magyar János (1961-) (élettanász) Zaza, Antonio Varró András (1954-) (farmakológus, klinikai farmakológus) Nánási Péter Pál (1956-) (élettanász)
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10.

001-es BibID:BIBFORM032923
035-os BibID:PMID:16086157
Első szerző:Birinyi Péter (élettanász)
Cím:Effects of SEA0400 and KB-R7943 on Na+/Ca2+ exchange current and L-type Ca2+ current in canine ventricular cardiomyocytes / Péter Birinyi, Károly Acsai, Tamás Bányász, András Tóth, Balázs Horváth, László Virág, Norbert Szentandrássy, János Magyar, András Varró, Ferenc Fülöp, Péter P. Nánási
Dátum:2005
ISSN:0028-1298
Megjegyzések:SEA0400 and KB-R7943 are compounds synthesised to block transsarcolemmal Na+/Ca2+ exchange current (INa/Ca); however, they Have also been shown to inhibit L-type Ca2+ current (ICa). The potential value of these compounds depends critically on their relative selectivity for INa/Ca over ICa. In the present work, therefore, the concentration-dependent effects of SEA0400 and KB-R7943 on INa/Ca and ICa were studied and compared in canine ventricular cardiomyocytes using the whole-cell configuration of the patch clamp technique. SEA0400 and KB-R7943 decreased INa/Ca in a concentration-dependent manner, having EC50 values of 111?43 nM and 3.35?0.82 mgrM, when suppressing inward currents, while the respective EC50 values were estimated at 108?18 nM and 4.74?0.69 mgrM in the case of outward current block. SEA0400 and KB-R7943 also blocked ICa, having comparable EC50 values (3.6 mgrM and 3.2 mgrM, respectively). At higher concentrations (10 mgrM) both drugs accelerated inactivation of ICa, retarded recovery from inactivation and shifted the voltage dependence of inactivation towards more negative voltages. The voltage dependence of activation was slightly modified by SEA0400, but not by KB-R7943. Based on the relatively good selectivity of submicromolar concentrations of SEA0400?but not KB-R7943?for INa/Ca over ICa, SEA0400 appears to be a suitable tool to study the role of INa/Ca in Ca2+ handling in canine cardiac cells. At concentrations higher than 1 mgrM, however, ICa is progressively suppressed by the compound.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
SEA0400
KB-R7943
Na+/Ca2+ exchanger
Ca2+ current
Cardiac cells
Dog
Voltage clamp
egyetemen (Magyarországon) készült közlemény
Megjelenés:Naunyn-Schmiedebergs Archives Of Pharmacology. - 372 : 1 (2005), p. 63-70. -
További szerzők:Acsai Károly Bányász Tamás (1960-) (élettanász) Tóth András Horváth Balázs (1981-) (élettanász) Virág László (élettanász Szeged) Szentandrássy Norbert (1976-) (élettanász) Magyar János (1961-) (élettanász) Varró András (1954-) (farmakológus, klinikai farmakológus) Fülöp Ferenc (Szeged) Nánási Péter Pál (1956-) (élettanász)
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Borító:

11.

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)
Internet cím:elektronikus változat
DOI
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12.

001-es BibID:BIBFORM004076
Első szerző:Farkas S. Attila
Cím:Na(+)/Ca(2+) exchanger inhibition exerts a positive inotropic effect in the rat heart, but fails to influence the contractility of the rabbit heart / Farkas A. S., Acsai K., Nagy N., Tóth A., Fülöp F., Seprényi G., Birinyi P., Nánási P. P., Forster T., Csanády M., Papp J. G., Varró A., Farkas A.
Dátum:2008
Megjegyzések:The Na(+)/Ca(2+) exchanger (NCX) may play a key role in myocardial contractility. The operation of the NCX is affected by the action potential (AP) configuration and the intracellular Na(+) concentration. This study examined the effect of selective NCX inhibition by 0.1, 0.3 and 1.0 microM SEA0400 on the myocardial contractility in the setting of different AP configurations and different intracellular Na(+) concentrations in rabbit and rat hearts. EXPERIMENTAL APPROACH: The concentration-dependent effects of SEA0400 on I(Na/Ca) were studied in rat and rabbit ventricular cardiomyocytes using a patch clamp technique. Starling curves were constructed for isolated, Langendorff-perfused rat and rabbit hearts. The cardiac sarcolemmal NCX protein densities of both species were compared by immunohistochemistry. KEY RESULTS: SEA0400 inhibited I(Na/Ca) with similar efficacy in the two species; there was no difference between the inhibitions of the forward or reverse mode of the NCX in either species. SEA0400 increased the systolic and the developed pressure in the rat heart in a concentration-dependent manner, for example, 1.0 microM SEA0400 increased the maximum systolic pressures by 12% relative to the control, whereas it failed to alter the contractility in the rabbit heart. No interspecies difference was found in the cardiac sarcolemmal NCX protein densities. CONCLUSIONS AND IMPLICATIONS: NCX inhibition exerted a positive inotropic effect in the rat heart, but it did not influence the contractility of the rabbit heart. This implies that the AP configuration and the intracellular Na(+) concentration may play an important role in the contractility response to NCX inhibition.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:British Journal of Pharmacology. - 154 : 1 (2008), p. 93-104. -
További szerzők:Acsai Károly Nagy N. (Szeged) Tóth A. Fülöp Ferenc (Szeged) Seprényi G. Birinyi Péter (1981-) (élettanász) Nánási Péter Pál (1956-) (élettanász) Forster Tamás Csanády Miklós (Szeged) Papp J. G. Varró András (1954-) (farmakológus, klinikai farmakológus) Farkas A. (Szeged)
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