1992 Fiscal Year Final Research Report Summary
Effects of hypoxia-reoxygenation on superoxide production and change of intra-cellular Ca^<++> of neutrophils
| Project/Area Number |
02670683
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
麻酔学
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
YUGE Osafumi Hiroshima University School of Medicine Professor, 医学部, 教授 (40034128)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAO Masakazu Hiroshima University School of Medicine Research Associate, 医学部, 助手 (90164128)
MORIWAKI Katsuyuki Hiroshima University Medical Hospital Assistant Professor, 医学部附属病院, 講師 (30157937)
FUJII Kohyu Hiroshima University School of Medicine Assistant Professor, 医学部, 講師 (60034021)
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| Project Period (FY) |
1990 – 1992
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| Keywords | Hypoxia / Neutrophils / Superoxide anion / Intra-cellular Ca^<++> ion / NADPH oxidase / Reoxygenation |
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| Research Abstract |
A study was made on the effects of hypoxia-reoxygenation on superoxide anion (O_2^-) production in neutrophils with the cytochrome C reduction method. Neutrophils were separated from the peripheral venous blood of healthy adults. The control group was treated with air PO_2 220mmHg). In the hypoxia group, neutrophils were treated with N_2 for 30 min. In the reoxygenation group, neutrophils were treated with oxygen for 15 min after pretreatment with N_2 for 30 min. Superoxide anion production was measured with the cytochrome C reduction method, after stimulation of phorbol myristate acetate or without such stimulation. Hypoxia caused a significant decrease of O_2^- production. Reoxygenation caused a significant increase of O_2^- production from unstimulated neutrophils. These results suggest that neutrophils were activated by hypoxia-reoxygenation.
As the second study, the effects of hypoxia-reoxygenation on NADPH oxidase activity and the change of intracellular Ca ion neutrophils were investigated. In the control group cell membranes of neutrophils were treated with air(PO_2 220mmHg). In the hypoxia group, cell membranes was treated with N_2 for 30 min (PO_2 28mmHg). In the reoxygenation group, cell membranes were treated with oxygen for 15 min after pretreatment with N_2 for 30 min (PO_2 480mmHg. In the oxygenation group, that was treated with oxygen for 15 min (PO_2 480mmHg). NADPH oxidase activity was measured with the cytochrome C reduction method. Hypoxia caused a significant decrease of NADPH oxidase activity. Reoxygenation caused significant increase of NADPH oxidase activity. These results suggest that NADPH oxidase was activated by hypoxia-reoxygenation.
Intracellular Ca ion was increased with reoxygenation. This finding suggested the increased intracellular Ca ion activates NADPH oxidase in the neutrophils.
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