Effect of 5-HT4 receptor stimulation on the pacemaker current I(f) in human isolated atrial myocytes
| Autor: | Elisabetta Cerbai, Gian Franco Montesi, Alessandro Mugelli, Giancarlo Calamai, Lucio Braconi, Massimo Cassai, Roberto Pino, Franco Alajmo, Alberto Borgioli |
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| Rok vydání: | 1999 |
| Předmět: |
Male
medicine.medical_specialty Indoles Patch-Clamp Techniques Physiology Diastole Atrial Appendage Action Potentials Stimulation Statistics Nonparametric Pacemaker potential Physiology (medical) Internal medicine Isoprenaline Atrial Fibrillation Medicine Myocyte Humans Aged Sulfonamides Atrium (architecture) business.industry Heart Middle Aged Bridged Bicyclo Compounds Heterocyclic Stimulation Chemical Electrophysiology Endocrinology Receptors Serotonin Benzimidazoles Female Receptors Serotonin 5-HT4 Serotonin Antagonists Cardiology and Cardiovascular Medicine business medicine.drug |
| Zdroj: | Università degli studi di Firenze-IRIS |
| ISSN: | 0008-6363 |
| Popis: | Objective: 5-HT4 receptors are present in human atrial cells and their stimulation has been implicated in the genesis of atrial arrhythmias including atrial fibrillation. An I f-like current has been recorded in human atrial myocytes, where it is modulated by s-adrenergic stimulation. In the present study, we investigated the effect of serotonin (5-hydroxytryptamine, 5-HT) on I f electrophysiological properties, in order to get an insight into the possible contribution of I f to the arrhythmogenic action of 5-HT in human atria. Methods: Human atrial myocytes were isolated by enzymatic digestion from samples of atrial appendage of patients undergoing corrective cardiac surgery. Patch-clamped cells were superfused with a modified Tyrode's solution in order to amplify I f and reduce overlapping currents. Results and conclusions: A time-dependent, cesium-sensitive increasing inward current, that we had previously described having the electrophysiological properties of the pacemaker current I f, was elicited by negative steps (−60 to −130 mV) from a holding potential of −40 mV. Boltzmann fit of control activation curves gave a midpoint ( V 1/2) of −88.9±2.6 mV ( n =14). 5-HT (1 μM) consistently caused a positive shift of V 1/2 of 11.0±2.0 mV ( n =8, p |
| Databáze: | OpenAIRE |
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