| Project/Area Number |
12470292
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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 |
Cerebral neurosurgery
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| Research Institution | Ehime University |
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Principal Investigator |
MAEDA Nobuji Ehime University, Faculty of Medicine, Professor, 医学部, 教授 (50036464)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Yoji Ehime University, Faculty of Medicine, Instructor, 医学部, 助手 (20226567)
TATEISHI Norihiko Ehime University Hospital, Associate Professor, 医学部附属病院, 助教授 (90236555)
TANAKA Junya Ehime University, Faculty of Medicine, Professor, 医学部, 教授 (70217040)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥11,100,000 (Direct Cost: ¥11,100,000)
Fiscal Year 2002: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2001: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2000: ¥7,000,000 (Direct Cost: ¥7,000,000)
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| Keywords | Microcirculation / Oxygen transport / Red blood cell rheology / Artificial micro-flow channel / Cerebral blood flow / Nervous tissues / Evoked potential / Image processing / 酸素放出 / 赤血球集合 / 重力 / 血流量 / 微小血管 / 脳循環 / トリグリセリド / 腸間膜微小血管網 / 赤血球 / 酸素飽和度 |
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| Research Abstract |
Effects of blood flow and hemorheological factors on oxygen (O_2) transport to brain and cerebral activity were comprehensively studied in microcirculatory level, in addition to the fundamental studies.
(1) Red blood cell (RBC) flow in microvessels varied in proportion to blood flow in main arteries. Close relationship between oxygenation state of blood and blood flow condition was observed.
(2) Effects of theological properties of RBCs on O_2 release were demonstrated using an O_2-permeable narrow tube, in relating to O_2 diffusion distance in RBCs and the surroundings.
(3) Oxygenation-deoxygenation process of blood affected RBC aggregation by pH-/CO_2-dependent shape changes of RBCs, and the enhancement of O_2 release was suggested at low pH and high CO_2 conditions.
(4) High-fat meal, even temporarily, enhanced RBC aggregation by increased triglycerides concentration in blood plasma. The phenomenon suggested microcirculatory disturbances and a risk for arteriosclerosis.
(5) Two-dimensional images of RBC flow and the oxygenation state in microvascular network, in addition to their cross-sectional images in single microvessels, were successfully constructed for brain cortex and mesentery.
(6) Flow behavior of RBCs in microvessels was changed more strikingly by vascular and hemorheological factors, as compared to their behavior in artificial narrow tubes. The phenomena were mainly due to the elasticity of the flow channels, such as in atherosclerotic change of blood vessels.
(7) Neural activity in brain was markedly influenced by O_2 transfer to the tissues through blood flow, as evaluated by evoked potential in sensory area.
(8) Mutual control mechanisms by humoral factors were found between functions of neurons and microglia.
In conclusion, this study strongly suggested that cerebral functions were influenced by O_2 transfer, which was modified not only by blood vessel factors, but also by hemorheological factors.
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