Effect of inhibitors of mitochondrial respiratory chain complexes on the electromechanical activity in human myocardium
| Autor: | Vida Gendvilienė, Jonas Jurevičius, Danguolė Zablockaitė, Irma Martišienė |
|---|---|
| Jazyk: | litevština |
| Rok vydání: | 2010 |
| Předmět: |
Male
medicine.medical_specialty Contraction (grammar) Antimycin A In Vitro Techniques human myocardium Electron Transport Electron Transport Complex IV chemistry.chemical_compound Electron Transport Complex III Myocardium Mitochondria heart Analysis Rotenone Anoxia Internal medicine medicine Repolarization Humans Enzyme Inhibitors Aged Heart Failure Electron Transport Complex I electromechanical activity anoxia Heart rotenone antimycin A General Medicine Middle Aged medicine.disease Myocardial Contraction 616.127 [udc] Endocrinology Mitochondrial respiratory chain chemistry Heart failure Coenzyme Q – cytochrome c reductase Female Perfusion |
| Zdroj: | Medicina, Kaunas : Lietuvos sveikatos mokslų universitetas, 2010, t. 46, Nr. 10, p. 679-685 Medicina; Volume 46; Issue 10; Pages: 679 Medicina Volume 46 Issue 10 |
| ISSN: | 1010-660X |
| Popis: | The aim of the study was to investigate the effect of inhibitors of mitochondrial respiratory chain complexes I, III, and IV on the electromechanical activity in human myocardium. Material and methods. The experiments were performed on the human myocardial strips obtained from patients with heart failure (NYHA class III or IV) using a conventional method of registration of myocardial electromechanical activity. Under the perfusion with physiological Tyrode solution (control), contraction force (P) was 0.94±0.12 mN (n=16), relaxation time (t50) was 173.38±5.03 ms (n=15), action potential durations measured at 50% (AP50) and 90% (AP90) repolarization were 248.96±13.38 ms and 398.59±17.93 ms, respectively (n=13). Results. The inhibition of respiratory chain complex I by rotenone (3×10–5 M, the highest concentration applied) decreased contraction force of human myocardium to 48.99%±14.74% (n=3) (P< 0.05) AP50, to 81.34%±15.81% and AP90, to 87.28%±7.25% (n=3) (P> 0.05) of control level, while relaxation time and resting tension remained almost unchanged. Antimycin A, an inhibitor of complex III, applied at the highest concentration (3×10–4 M) reduced P to 41.66%±8.8% (n=5) (P< 0.001) and marginally increased t50 and decreased the durations of AP. Anoxia (3 mM Na2S2O4) that inhibits the activity of complex IV reduced the contraction force to 9.23%±3.56% (n=6) (P< 0.001), AP50 and AP90 to 65.46%±9.95% and 71.07%±8.39% (n=5) (P< 0.05) of control level, respectively furthermore, the resting tension augmented (contracture developed). Conclusions. Our results show that the inhibition of respiratory chain complex IV had the strongest inhibitory effect on the electromechanical activity of failing human myocardium. |
| Databáze: | OpenAIRE |
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