| Project/Area Number |
04671011
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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 |
Obstetrics and gynecology
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| Research Institution | Miyazaki Medical College |
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Principal Investigator |
IKENOUE Tsuyomu Faculty of Medicine, Miyazaki Medical College, Professor, 医学部, 教授 (60232211)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAMOTO Hiroshi Faculty of Agriculture, Kagoshima University, Professor, 農学部, 教授 (20041650)
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| Project Period (FY) |
1992 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1994: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | fetus / hypoxemia / blood flow redistribution / magnesium / preterm / 胎児低酸素血症 / ヤギ / 慢性実験 / 脳血流量 / 腎血流量 / 胎児仮死 / 硫酸マグネシウム / マイクロスフェア法 |
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| Research Abstract |
We first utilized a colored microsphere technique to measure blood flow in fetal tissue, that resulted in similar patterns comparable to a radioactive microsphere method. Thus, by using this colored microsphere method, we subsequently measured the brain blood flow in fetal sheep models during an acute phase of hypoxemia.
Blood flow increases in the midbrain and medulla were significantly lager than that of the cerebral cortex during hypoxemia. Subsequently, we focused on the developing changes in hypoxemic blood flow distribution between nea term (0.85 gestation) and preterm (0.7 gestation). In this series of experiments, blood flow increase during hypoxemia in the preterm fetuses was almost similar to that in the near term fetuses. One exception was that hippocampal blood flow was more increased in the preterm than in the near term. Finally, we studied the effects of magnesium sulfate on hypoxemic responses during hypoxemia, since magnesium were commonly used in clinical practice. This experiment showed that hypoxemic increase in blood flow to the cerebral cortex, heart, and adrenal were maintained under magnesium infusion, compared to its controls. Interestingly, we also observed that magnesium did not slow fetal heart rate or increase blood pressure during hypoxemia.
In conclusion, fetal blood flow can be measured with the colored microsphere method. Using this, we have shown that hypoxemic changes in blood flow distribution is basically maintained in the preterm fetuses and in fetuses under magnesium administration.
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