title: Heptanol decreases the incidence of ischemia-induced ventricular arrhythmias through altering electrophysiological properties and connexin 43 in rat hearts.
abstract: Heptanol is a type of gap junction inhibitor that decreases electrical conduction velocity. However, little is known regarding the effects of heptanol on the arrhythmias induced by regional myocardial ischemia. This study aimed to investigate the effects of heptanol on ventricular arrhythmias and the underlying mechanisms. On the Langendorff apparatus, isolated hearts of Sprague-Dawley rats underwent 30 min of ischemia, with or without pretreatment with heptanol (0.1, 0.3 or 0.5 mM), 15 min prior to the induction of regional ischemia through ligation of the left anterior descending coronary artery. The incidence of ventricular tachycardia (VT) and ventricular fibrillation (VF) were recorded after ligation. Heptanol decreased the incidence of ventricular arrhythmias (45% in the control group vs. 10% in the 0.1 mM group, 0% in the 0.3 mM group and 0% in the 0.5 mM group, P<0.05), whereas it prolonged the PR interval, QT interval and monophasic action potential duration at 90% repolarization (MAPD90). As evaluated with immunofluorescence microscopy, heptanol was able to partly reverse the downregulation of connexin 43 (Cx43) induced by ischemia. The results of the reverse transcription-polymerase chain reaction were consistent with those of immunofluorescence. In conclusion, heptanol significantly decreased the incidence of VT and VF induced by regional ischemia and prolonged the PR interval, QT interval and MAPD90. Heptanol also partly reversed the downregulation of Cx43 induced by ischemia.
authors.affiliation: Department of Cardiology, Tongji Hospital, Tongji University, Shanghai, P.R. China.
authors.forename: Bing
authors.initials: B
authors.lastname: Sun
authors.affiliation: Department of Cardiology, Taida Cardiology Hospital, Tianjin, P.R. China.
authors.forename: Xiangqian
authors.initials: X
authors.lastname: Qi
authors.affiliation: Department of Cardiology, Tongji Hospital, Tongji University, Shanghai, P.R. China.
authors.forename: Jinfa
authors.initials: J
authors.lastname: Jiang
keywords: electrophysiology; gap junction; heptanol; myocardial ischemia; ventricular arrhythmia
references.citation: Biophys J. 1994 Jul;67(1):113-9
references.pmid: 7522596
references.citation: Am J Physiol Heart Circ Physiol. 2000 May;278(5):H1662-70
references.pmid: 10775147
references.citation: Circ Res. 1998 Mar 23;82(5):604-12
references.pmid: 9529165
references.citation: J Physiol Sci. 2012 Mar;62(2):79-92
references.pmid: 22219003
references.citation: Circulation. 1991 Feb;83(2):614-21
references.pmid: 1991379
references.citation: Am J Physiol Heart Circ Physiol. 2011 Dec;301(6):H2442-53
references.pmid: 21949115
references.citation: Circulation. 2001 Sep 25;104(13):1544-9
references.pmid: 11571250
references.citation: Curr Opin Cardiol. 2012 May;27(3):236-41
references.pmid: 22382502
references.citation: J Cardiovasc Electrophysiol. 1996 Dec;7(12):1159-71
references.pmid: 8985805
references.citation: J Am Coll Cardiol. 2012 Sep 18;60(12):1111-3
references.pmid: 22883635
references.citation: J Cardiovasc Pharmacol. 1994 Nov;24(5):826-40
references.pmid: 7532762
references.citation: J Mol Cell Cardiol. 2001 Feb;33(2):359-71
references.pmid: 11162139
references.citation: Acta Pharmacol Sin. 2004 Nov;25(11):1458-63
references.pmid: 15525468
references.citation: Biochim Biophys Acta. 2012 Aug;1818(8):1831-43
references.pmid: 21856279
references.citation: J Mol Cell Cardiol. 2001 Dec;33(12):2145-55
references.pmid: 11735261
references.citation: Am J Physiol Heart Circ Physiol. 2002 Sep;283(3):H1116-22
references.pmid: 12181142
references.citation: Cardiovasc Res. 2008 Oct 1;80(1):9-19
references.pmid: 18519446
references.citation: Sheng Li Xue Bao. 2011 Dec 25;63(6):586-92
references.pmid: 22193455
references.citation: Heart Rhythm. 2012 Feb;9(2):308-11
references.pmid: 21939627