Calcium Transient and Sodium-Calcium Exchange Current in Human versus Rabbit Sinoatrial Node Pacemaker Cells
There is an ongoing debate on the mechanism underlying the pacemaker activity of sinoatrial node (SAN) cells, focusing on the relative importance of the “membrane clock” and the “Ca2+ clock” in the generation of the small net membrane current that depolarizes the cell towards the action potential th...
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| Format: | Article |
| Language: | English |
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Wiley
2013-01-01
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| Series: | The Scientific World Journal |
| Online Access: | http://dx.doi.org/10.1155/2013/507872 |
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| author | Arie O. Verkerk Marcel M. G. J. van Borren Ronald Wilders |
| author_facet | Arie O. Verkerk Marcel M. G. J. van Borren Ronald Wilders |
| author_sort | Arie O. Verkerk |
| collection | DOAJ |
| description | There is an ongoing debate on the mechanism underlying the pacemaker activity of sinoatrial node (SAN) cells, focusing on the relative importance of the “membrane clock” and the “Ca2+ clock” in the generation of the small net membrane current that depolarizes the cell towards the action potential threshold. Specifically, the debate centers around the question whether the membrane clock-driven hyperpolarization-activated current, If, which is also known as the “funny current” or “pacemaker current,” or the Ca2+ clock-driven sodium-calcium exchange current, INaCa, is the main contributor to diastolic depolarization. In our contribution to this journal’s “Special Issue on Cardiac Electrophysiology,” we present a numerical reconstruction of If and INaCa in isolated rabbit and human SAN pacemaker cells based on experimental data on action potentials, If, and intracellular calcium concentration ([Ca2+]i) that we have acquired from these cells. The human SAN pacemaker cells have a smaller If, a weaker [Ca2+]i transient, and a smaller INaCa than the rabbit cells. However, when compared to the diastolic net membrane current, INaCa is of similar size in human and rabbit SAN pacemaker cells, whereas If is smaller in human than in rabbit cells. |
| format | Article |
| id | doaj-art-e6c7ec8dbf864c2baae94ea433e49471 |
| institution | Kabale University |
| issn | 1537-744X |
| language | English |
| publishDate | 2013-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | The Scientific World Journal |
| spelling | doaj-art-e6c7ec8dbf864c2baae94ea433e494712025-02-03T05:54:10ZengWileyThe Scientific World Journal1537-744X2013-01-01201310.1155/2013/507872507872Calcium Transient and Sodium-Calcium Exchange Current in Human versus Rabbit Sinoatrial Node Pacemaker CellsArie O. Verkerk0Marcel M. G. J. van Borren1Ronald Wilders2Department of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The NetherlandsLaboratory of Clinical Chemistry and Hematology, Jeroen Bosch Hospital, Henri Dunantstraat 1, 5223 GZ 's-Hertogenbosch, The NetherlandsDepartment of Anatomy, Embryology and Physiology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The NetherlandsThere is an ongoing debate on the mechanism underlying the pacemaker activity of sinoatrial node (SAN) cells, focusing on the relative importance of the “membrane clock” and the “Ca2+ clock” in the generation of the small net membrane current that depolarizes the cell towards the action potential threshold. Specifically, the debate centers around the question whether the membrane clock-driven hyperpolarization-activated current, If, which is also known as the “funny current” or “pacemaker current,” or the Ca2+ clock-driven sodium-calcium exchange current, INaCa, is the main contributor to diastolic depolarization. In our contribution to this journal’s “Special Issue on Cardiac Electrophysiology,” we present a numerical reconstruction of If and INaCa in isolated rabbit and human SAN pacemaker cells based on experimental data on action potentials, If, and intracellular calcium concentration ([Ca2+]i) that we have acquired from these cells. The human SAN pacemaker cells have a smaller If, a weaker [Ca2+]i transient, and a smaller INaCa than the rabbit cells. However, when compared to the diastolic net membrane current, INaCa is of similar size in human and rabbit SAN pacemaker cells, whereas If is smaller in human than in rabbit cells.http://dx.doi.org/10.1155/2013/507872 |
| spellingShingle | Arie O. Verkerk Marcel M. G. J. van Borren Ronald Wilders Calcium Transient and Sodium-Calcium Exchange Current in Human versus Rabbit Sinoatrial Node Pacemaker Cells The Scientific World Journal |
| title | Calcium Transient and Sodium-Calcium Exchange Current in Human versus Rabbit Sinoatrial Node Pacemaker Cells |
| title_full | Calcium Transient and Sodium-Calcium Exchange Current in Human versus Rabbit Sinoatrial Node Pacemaker Cells |
| title_fullStr | Calcium Transient and Sodium-Calcium Exchange Current in Human versus Rabbit Sinoatrial Node Pacemaker Cells |
| title_full_unstemmed | Calcium Transient and Sodium-Calcium Exchange Current in Human versus Rabbit Sinoatrial Node Pacemaker Cells |
| title_short | Calcium Transient and Sodium-Calcium Exchange Current in Human versus Rabbit Sinoatrial Node Pacemaker Cells |
| title_sort | calcium transient and sodium calcium exchange current in human versus rabbit sinoatrial node pacemaker cells |
| url | http://dx.doi.org/10.1155/2013/507872 |
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