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001-es BibID:	BIBFORM030253
Első szerző:	Bányász Tamás (élettanász)
Cím:	Different effects of endothelin-1 on calcium and potassium currents in canine ventricular cells / Tamás Bányász, János Magyar, Ágnes Körtvély, Gyula Szigeti, Péter Szigligeti, Zoltán Papp, Attila Mohácsi, László Kovács, Péter P. Nánási
Dátum:	2001
ISSN:	0028-1298
Megjegyzések:	Effects of endothelin-l (ET-1) on the L-type calcium current (I-Ca) and delayed rectifier potassium current (I-K) were studied in isolated canine ventricular cardiomyocytes using the whole-cell configuration of the patch-clamp technique. ET-1 (8 nM) was applied in three experimental arrangements: untreated cells, in the presence of 50 nM isoproterenol, and in the presence of 250 muM 8-bromo-cAMP. In untreated cells, ET-1 significantly decreased the peak amplitude of I-Ca by 32.3 +/-4.8% at +5 mV (P<0.05) without changing activation or inactivation characteristics of I-Ca. ET-1 had no effect on the amplitude of I-K, I-to (transient outward current) or I-K1 (inward rectifier K current) in untreated cells; however, the time course of recovery from inactivation of I-to was significantly increased by ET-1 (from 26.5<plus/minus>6 ms to 59.5 +/- 1.8 ms, P<0.05). Amplitude and time course of intracellular calcium transients, recorded in voltage-clamped cells previously loaded with the fluorescent calcium indicator dye Fura-2, were not affected by ET-1. ET-1 had no effect on force of contraction in canine ventricular trabeculae. Isoproterenol increased the amplitude of I-Ca to 263<plus/minus> 29% of control. ET-1 reduced I-Ca also in isoproterenol-treated cells by 17.8 +/-2% (P<0.05); this inhibition was significantly less than obtained in untreated cells. I-K was increased by isoproterenol to 213<plus/minus>18% of control. This effect of isoproterenol on I-K was reduced by 31.8 +/-4.8% if the cells were pretreated with ET-1. Similarly, in isoproterenol-treated cells ET-1 decreased I-K by 16.2 +/-1.5% (P<0.05). Maximal activation of protein kinase A (PKA) was achieved by application of 8-bromo-cAMP in the pipette solution. In the presence of 8-bromo-cAMP ET-l failed to alter I-CA or I-K It was concluded that differences in effects of ET-1 on I-CA and I-K may be related to differences in cAMP sensitivity of the currents.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban egyetemen (Magyarországon) készült közlemény
Megjelenés:	Naunyn-Schmiedebergs Archives of Pharmacology. - 363 : 4 (2001), p. 383-390. -
További szerzők:	Magyar János (1961-) (élettanász) Körtvély Ágnes Szigeti Gyula (1969-) (élettanász, elektrofiziológus) Szigligeti Péter Papp Zoltán (1965-) (kardiológus, élettanász) Mohácsi Attila (1960-) (orvos) Kovács László (1939-) (élettanász) Nánási Péter Pál (1956-) (élettanász)
Internet cím:	DOI elektronikus változat Intézményi repozitóriumban (DEA) tárolt változat
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