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The effects of serotonin on the electrophysiological properties of atrioventricular node during an experimental atrial fibrillation

Changizi, S. and Khori, V. and Alizadeh, A.M. (2015) The effects of serotonin on the electrophysiological properties of atrioventricular node during an experimental atrial fibrillation. Naunyn-Schmiedeberg's Archives of Pharmacology, 388 (8). pp. 843-852.

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Abstract

Abstract A few studies explored the atrioventricular (AV) nodal effects of 5-hydroxytyptamine (serotonin, 5-HT) during supraventricular tachyarrhythmia. The aims of the present study are to investigate (i) 5-HT effects on the rate-dependent electrophysiological functions of AV node during atrial fibrillation (AF) and (ii) the potential contribution of various 5-HT receptors and the role of the autonomic nervous system on 5-HT effects on AV nodal properties. The specific stimulation protocols were applied to detect the electrophysiological parameters of AV node in seven groups of isolated rabbit AV nodal preparations (N = 75) in the presence of 5-HT (0.5, 1, 5, 10, and 20 μM) and its receptor antagonists, nadolol and atropine. The simulated AF protocol was executed in a separate group, and specific indices, including mean His-His interval, a zone of concealment (ZOC), and concealed beats recorded. 5-HT (10-20 μM) increased significantly functional refractory period, Wenckebach cycle length, and excitability index (p < 0.05). The percentage of gap and echo beats was significantly decreased with increasing 5-HT concentrations (p < 0.05). Ketanserin and tropisetron increased significantly atrial-His conduction time, effective refractory period, and Wenckebach cycle length (p < 0.05). 5-HT effects on functional refractory period and Wenckebach cycle length were abrogated by tropisetron and nadolol (p < 0.05). 5-HT elicited prolongation of ZOC and nodal refractoriness (p < 0.05). We conclude that 5-HT elicited prolongation of the nodal refractoriness more than atrial-His conduction time leads to increase in the excitability index and ZOC without significant reduction of the ventricular rates during AF. © 2015 Springer-Verlag Berlin Heidelberg.

Item Type: Article
Additional Information: cited By 0
Uncontrolled Keywords: adrenergic receptor; atropine; nadolol; serotonin; serotonin antagonist; serotonin receptor; tropisetron, animal experiment; animal model; animal tissue; Article; autonomic nervous system; controlled study; drug effect; electrophysiological procedures; experimental atrial fibrillation; experimental rabbit; heart atrioventricular node; heart conduction; heart muscle excitability; heart muscle refractory period; His bundle; male; nonhuman; Wenckebach period
Subjects: مقالات نمایه شده محققین دانشگاه در سایت ,Web of Science ,Scopus
Divisions: معاونت تحقیقات و فناوری
Depositing User: GOUMS
Date Deposited: 10 Sep 2016 04:51
Last Modified: 16 Jan 2017 18:57
URI: http://eprints.goums.ac.ir/id/eprint/4689

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