2004 Fiscal Year Final Research Report Summary
Development of the imaging system to evaluate of blood flow distribution and metabolic activity in myocardial microcirculation.
| Project/Area Number |
15300174
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | Kawasaki Medical School |
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Principal Investigator |
OGASAWARA Yasuo Kawasaki Medical School, Medical Engineering, Associate Professor, 医学部, 助教授 (10152365)
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| Co-Investigator(Kenkyū-buntansha) |
YADA Toyotaka Kawasaki Medical School, Medical Engineering, Assistant Professor, 医学部, 講師 (00210279)
NAKAMOTO Hiroshi Kawasaki Medical School, Medical Engineering, Research Associate, 医学部, 助手 (10299183)
MATSUMOTO Takeshi Osaka University, Graduate School of Engineering Science, Associate Professor, 大学院・基礎工学研究科, 助教授 (30249560)
KAJIYA Fumihiko Okayama University, Graduate School of Medical and Dentistry, Professor, 大学院・医歯学総合研究科, 教授 (70029114)
MOCHIZUKI Seiichi Kawasaki College of Allied Health Professions, Medical Engineering, Associate Professor, 臨床工学科, 助教授 (60259596)
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| Project Period (FY) |
2003 – 2004
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| Keywords | microcirculation / myocardium / metabolic activity / imaging / blood flow dictribution / NADH / mitochondria / oxygen tension |
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| Research Abstract |
We constructed the fluorescence microscope system for imaging of myocardial metabolic activity and blood flow distribution. To measure erythrocyte velocities in microcirculation under in-vivo condition with an intravital videomicroscope, the newly software was developed. A line segment was set along the capillaries in time-sequential videotaped images and then a spatiotemporal image was constructed along that segment. The angle of striped pattern in the spatiotemporal image which reflects the erythrocyte velocity, was estimated to compute erythrocyte velocity vector mapping. We have succeeded in quantitatively evaluating the in-vivo microcirculation with our videomicroscope system and by spatiotemporal image analyzing method. Regional myocardial vulnerability to dysoxia is heterogeneous ; however, the dynamics of regional dysoxia and the dependence of regional dysoxia on flow heterogeneity are not well understood, especially at a microcirculatory level. Thus, we evaluated epimyocardial NADH fluorescence during stepwise changes in oxygenation and made a comparison between NADH fluorescence and flow distributions, resolved into 0.1×0.1- to 0.4×0.4-mm^2 regions the sizes comparable to a microcirculatory unit, which perfused by a single precapillary arteriole. In another hypoxia-perfused hearts showing the stable patchy fluorescence pattern, tritium-labeled desmethylimipramine was infused and its deposition distribution, i.e., relative flow distribution within epimyocardial layers was measured by digital radiography. The region of higher NADH fluorescence tended to receive lower flow ; the regional flow-fluorescence correlation was significant. These results suggest that regions vulnerable to dysoxia are also hard to recover from dysoxia and that regional vulnerability to dysoxia is highly relevant to regional flow heterogeneity at a microcirculatory level.
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