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Electrophysiological and arrhythmogenic effects of 5-hydroxytryptamine on human atrial cells are reduced in atrial fibrillation

5-Hydroxytryptamine (5-HT) is proarrhythmic in atrial cells from patients in sinus rhythm (SR) via activation of 5-HT(4) receptors, but its effects in atrial cells from patients with atrial fibrillation (AF) are unknown. The whole-cell perforated patch-clamp technique was used to record L-type Ca(2+...

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Autores principales: Pau, Davide, Workman, Antony J., Kane, Kathleen A., Rankin, Andrew C.
Formato: Texto
Lenguaje:English
Publicado: Academic Press 2007
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2526346/
https://www.ncbi.nlm.nih.gov/pubmed/16989857
http://dx.doi.org/10.1016/j.yjmcc.2006.08.007
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author Pau, Davide
Workman, Antony J.
Kane, Kathleen A.
Rankin, Andrew C.
author_facet Pau, Davide
Workman, Antony J.
Kane, Kathleen A.
Rankin, Andrew C.
author_sort Pau, Davide
collection PubMed
description 5-Hydroxytryptamine (5-HT) is proarrhythmic in atrial cells from patients in sinus rhythm (SR) via activation of 5-HT(4) receptors, but its effects in atrial cells from patients with atrial fibrillation (AF) are unknown. The whole-cell perforated patch-clamp technique was used to record L-type Ca(2+) current (I(CaL)), action potential duration (APD) and arrhythmic activity at 37 °C in enzymatically isolated atrial cells obtained from patients undergoing cardiac surgery, in SR or with chronic AF. In the AF group, 5-HT (10 μM) produced an increase in I(CaL) of 115 ± 21% above control (n = 10 cells, 6 patients) that was significantly smaller than that in the SR group (232 ± 33%; p < 0.05; n = 27 cells, 12 patients). Subsequent co-application of isoproterenol (1 μM) caused a further increase in I(CaL) in the AF group (by 256 ± 94%) that was greater than that in the SR group (22 ± 6%; p < 0.05). The APD at 50% repolarisation (APD(50)) was prolonged by 14 ± 3 ms by 5-HT in the AF group (n = 37 cells, 14 patients). This was less than that in the SR group (27 ± 4 ms; p < 0.05; n = 58 cells, 24 patients). Arrhythmic activity in response to 5-HT was observed in 22% of cells in the SR group, but none was observed in the AF group (p < 0.05). Atrial fibrillation was associated with reduced effects of 5-HT, but not of isoproterenol, on I(CaL) in human atrial cells. This reduced effect on I(CaL) was associated with a reduced APD(50) and arrhythmic activity with 5-HT. Thus, the potentially arrhythmogenic influence of 5-HT may be suppressed in AF-remodelled human atrium.
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spelling pubmed-25263462008-08-28 Electrophysiological and arrhythmogenic effects of 5-hydroxytryptamine on human atrial cells are reduced in atrial fibrillation Pau, Davide Workman, Antony J. Kane, Kathleen A. Rankin, Andrew C. J Mol Cell Cardiol Original Article 5-Hydroxytryptamine (5-HT) is proarrhythmic in atrial cells from patients in sinus rhythm (SR) via activation of 5-HT(4) receptors, but its effects in atrial cells from patients with atrial fibrillation (AF) are unknown. The whole-cell perforated patch-clamp technique was used to record L-type Ca(2+) current (I(CaL)), action potential duration (APD) and arrhythmic activity at 37 °C in enzymatically isolated atrial cells obtained from patients undergoing cardiac surgery, in SR or with chronic AF. In the AF group, 5-HT (10 μM) produced an increase in I(CaL) of 115 ± 21% above control (n = 10 cells, 6 patients) that was significantly smaller than that in the SR group (232 ± 33%; p < 0.05; n = 27 cells, 12 patients). Subsequent co-application of isoproterenol (1 μM) caused a further increase in I(CaL) in the AF group (by 256 ± 94%) that was greater than that in the SR group (22 ± 6%; p < 0.05). The APD at 50% repolarisation (APD(50)) was prolonged by 14 ± 3 ms by 5-HT in the AF group (n = 37 cells, 14 patients). This was less than that in the SR group (27 ± 4 ms; p < 0.05; n = 58 cells, 24 patients). Arrhythmic activity in response to 5-HT was observed in 22% of cells in the SR group, but none was observed in the AF group (p < 0.05). Atrial fibrillation was associated with reduced effects of 5-HT, but not of isoproterenol, on I(CaL) in human atrial cells. This reduced effect on I(CaL) was associated with a reduced APD(50) and arrhythmic activity with 5-HT. Thus, the potentially arrhythmogenic influence of 5-HT may be suppressed in AF-remodelled human atrium. Academic Press 2007-01 /pmc/articles/PMC2526346/ /pubmed/16989857 http://dx.doi.org/10.1016/j.yjmcc.2006.08.007 Text en © 2007 Elsevier Ltd. https://creativecommons.org/licenses/by-nc-nd/3.0/ Open Access under CC BY-NC-ND 3.0 (https://creativecommons.org/licenses/by-nc-nd/3.0/) license
spellingShingle Original Article
Pau, Davide
Workman, Antony J.
Kane, Kathleen A.
Rankin, Andrew C.
Electrophysiological and arrhythmogenic effects of 5-hydroxytryptamine on human atrial cells are reduced in atrial fibrillation
title Electrophysiological and arrhythmogenic effects of 5-hydroxytryptamine on human atrial cells are reduced in atrial fibrillation
title_full Electrophysiological and arrhythmogenic effects of 5-hydroxytryptamine on human atrial cells are reduced in atrial fibrillation
title_fullStr Electrophysiological and arrhythmogenic effects of 5-hydroxytryptamine on human atrial cells are reduced in atrial fibrillation
title_full_unstemmed Electrophysiological and arrhythmogenic effects of 5-hydroxytryptamine on human atrial cells are reduced in atrial fibrillation
title_short Electrophysiological and arrhythmogenic effects of 5-hydroxytryptamine on human atrial cells are reduced in atrial fibrillation
title_sort electrophysiological and arrhythmogenic effects of 5-hydroxytryptamine on human atrial cells are reduced in atrial fibrillation
topic Original Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2526346/
https://www.ncbi.nlm.nih.gov/pubmed/16989857
http://dx.doi.org/10.1016/j.yjmcc.2006.08.007
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