Role of the reverse mode of the Na+/Ca2+ exchanger in reoxygenation-induced cardiomyocyte injury
| Autor: | H. M. Piper, S. Haffner, Matthias Schäfer, Javier Inserte, Yury Ladilov, Claudia Schäfer, David Garcia-Dorado |
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| Rok vydání: | 2001 |
| Předmět: |
Male
medicine.medical_specialty Time Factors Physiology Ischemia chemistry.chemical_element Myocardial Reperfusion Injury Calcium Sodium-Calcium Exchanger Rats Sprague-Dawley chemistry.chemical_compound Cytosol Reperfusion therapy Physiology (medical) Internal medicine Lactate dehydrogenase medicine Animals Myocyte Rats Wistar Cells Cultured Cell Size Analysis of Variance business.industry Myocardium Sodium Thiourea Hydrogen-Ion Concentration medicine.disease Rats Perfusion Preload Endocrinology chemistry Models Animal Cardiology and Cardiovascular Medicine business Reperfusion injury |
| Zdroj: | Cardiovascular Research. 51:241-250 |
| ISSN: | 0008-6363 |
| DOI: | 10.1016/s0008-6363(01)00282-6 |
| Popis: | Objective: We have recently shown that spontaneous Ca2+ oscillations elicit irreversible hypercontracture of cardiomyocytes during reoxygenation. The aim of this study was to investigate whether influx of exterior Ca2+ through the reverse mode of the Na+/Ca2+ exchanger (NCE) contributes to the development of these oscillations and, therefore, to reoxygenation-induced hypercontracture. Methods: Isolated cardiomyocytes and hearts from rats were used as models. Cardiomyocytes were exposed to 60 min simulated ischemia (pHo 6.4) and 10 min reoxygenation (pHo 7.4). During reoxygenation cardiomyocytes were superfused with medium containing 1 mmol/l Ca2+ (control), with nominally Ca2+-free medium or with medium containing 10 μmol/l KB-R 7943 (KB), a selective inhibitor of the reverse mode of the NCE. Results: In reoxygenated cardiomyocytes rapid Ca2+ oscillations occurred which were reduced under Ca2+-free conditions or in presence of KB. Hypercontracture was also significantly reduced under Ca2+-free conditions or in presence of KB. After 30 min of normoxic perfusion isolated rat hearts were subjected to 60 min global ischemia and reperfusion. KB (10 μmol/l) was present during the first 10 min of reperfusion. LVEDP, LVdevP and lactate dehydrogenase (LDH) release were measured. Presence of KB reduced post-ischemic LVEDP and improved left ventricular function (LVdevP). In KB treated hearts the reperfusion induced release of LDH was markedly reduced from 81.1±9.9 (control) to 49.3±8.8 U/60 min/g dry weight. Conclusion: Our study shows that inhibition of the reverse mode of the NCE, during reperfusion only, protects cardiomyocytes and whole hearts against reperfusion injury. |
| Databáze: | OpenAIRE |
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