| Presentation | 2006-03-15 Metabolic changes in the myocardium associated with transitions from ventricular tachycardia to fibrillation in isolated rat hearts. Junichi Miyaki, Yoshiko Yamauchi, Koichi Kawahara, |
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| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | It is well known that ventricular tachycardia (VT), in most cases, precedes ventricular fibrillation (VF), a lethal ventricular tachyarrhythmia leading to sudden cardiac death. However, the detailed mechanisms responsible for the transition from VT to VF have not been fully understood at present. Our previous studies have revealed that an increase in the Ca^<2+> uptake by mitochondria during sustained VT is critical to the VT/VF transition, suggesting that the metabolic status of the myocardium concurrently changes associating with the transition, since mitochondria are the primary ATP-producing organelle in the heart. This study aims to clarify whether and how metabolic changes in the myocardium are involved in the VT/VF transition by using Langendorff-per fused rat's hearts. The results in this study demonstrated that the production of ATP in the myocardium nearly met the energy demand of the heart during VT, but the energy balance was collapsed during VF. The present study suggested that an increase in the concentration of Ca^<2+> in the micro-domain surrounding the mouth of L-type Ca^<2+> channels, sarcoplasmic reticulum (SR), and mitochondria during sustained VT led to the increased uptake of Ca^<2+> by mitochondria, resulting in the activation of L-type Ca^<2+> channels leading to the VT/VF transition. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | Arrhythmias / VT/VF transition / F_1F_0-ATPase / Intracellular Ca^<2+> / L-type Ca^<2+> channel |
| Paper # | MBE2005-137 |
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| Conference Information | |
| Committee | MBE |
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| Conference Date | 2006/3/8(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | |
| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | ME and Bio Cybernetics (MBE) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Metabolic changes in the myocardium associated with transitions from ventricular tachycardia to fibrillation in isolated rat hearts. |
| Sub Title (in English) | |
| Keyword(1) | Arrhythmias |
| Keyword(2) | VT/VF transition |
| Keyword(3) | F_1F_0-ATPase |
| Keyword(4) | Intracellular Ca^<2+> |
| Keyword(5) | L-type Ca^<2+> channel |
| 1st Author's Name | Junichi Miyaki |
| 1st Author's Affiliation | Graduate School of Information Science & Technology, Hokkaido University() |
| 2nd Author's Name | Yoshiko Yamauchi |
| 2nd Author's Affiliation | Graduate School of Information Science & Technology, Hokkaido University |
| 3rd Author's Name | Koichi Kawahara |
| 3rd Author's Affiliation | Graduate School of Information Science & Technology, Hokkaido University |
| Date | 2006-03-15 |
| Paper # | MBE2005-137 |
| Volume (vol) | vol.105 |
| Number (no) | 655 |
| Page | pp.pp.- |
| #Pages | 4 |
| Date of Issue | |