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Nagy ZA, Virág L, Tóth A, Biliczki P, Acsai K, Bányász T, Nánási P, Papp JG, Varró A. Selective inhibition of sodium-calcium exchanger by SEA-0400 decreases early and delayed after depolarization in canine heart. Br J Pharmacol 2004; 143:827-31. [PMID: 15504749 PMCID: PMC1575948 DOI: 10.1038/sj.bjp.0706026] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2004] [Revised: 07/27/2004] [Accepted: 09/22/2004] [Indexed: 11/08/2022] Open
Abstract
The sodium-calcium exchanger (NCX) was considered to play an important role in arrhythmogenesis under certain conditions such as heart failure or calcium overload. In the present study, the effect of SEA-0400, a selective inhibitor of the NCX, was investigated on early and delayed afterdepolarizations in canine ventricular papillary muscles and Purkinje fibres by applying conventional microelectrode techniques at 37 degrees C. The amplitude of both early and delayed afterdepolarizations was markedly decreased by 1 microM SEA-0400 from 26.6+/-2.5 to 14.8+/-1.8 mV (n=9, P<0.05) and from 12.5+/-1.7 to 5.9+/-1.4 mV (n=3, P<0.05), respectively. In enzymatically isolated canine ventricular myocytes, SEA-0400 did not change significantly the L-type calcium current and the intracellular calcium transient, studied using the whole-cell configuration of the patch-clamp technique and Fura-2 ratiometric fluorometry. It is concluded that, through the reduction of calcium overload, specific inhibition of the NCX current by SEA-0400 may abolish triggered arrhythmias.
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Affiliation(s)
- Zsolt A Nagy
- Department of Pharmacology & Pharmacotherapy, Albert Szent-Györgyi Medical Center, Faculty of Medicine, University of Szeged, Dóm tér 12, PO Box 427, Szeged, Hungary
| | - László Virág
- Department of Pharmacology & Pharmacotherapy, Albert Szent-Györgyi Medical Center, Faculty of Medicine, University of Szeged, Dóm tér 12, PO Box 427, Szeged, Hungary
| | - András Tóth
- Department of Pharmacology & Pharmacotherapy, Albert Szent-Györgyi Medical Center, Faculty of Medicine, University of Szeged, Dóm tér 12, PO Box 427, Szeged, Hungary
| | - Péter Biliczki
- Department of Pharmacology & Pharmacotherapy, Albert Szent-Györgyi Medical Center, Faculty of Medicine, University of Szeged, Dóm tér 12, PO Box 427, Szeged, Hungary
| | - Károly Acsai
- Department of Pharmacology & Pharmacotherapy, Albert Szent-Györgyi Medical Center, Faculty of Medicine, University of Szeged, Dóm tér 12, PO Box 427, Szeged, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Julius Gy Papp
- Department of Pharmacology & Pharmacotherapy, Albert Szent-Györgyi Medical Center, Faculty of Medicine, University of Szeged, Dóm tér 12, PO Box 427, Szeged, Hungary
- Division of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary
| | - András Varró
- Department of Pharmacology & Pharmacotherapy, Albert Szent-Györgyi Medical Center, Faculty of Medicine, University of Szeged, Dóm tér 12, PO Box 427, Szeged, Hungary
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