权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Changes in fetal tissue blood flow under long-term hypoxemia

长期低氧血症下胎儿组织血流变化

基本信息

批准号：
04671011
负责人：
IKENOUE Tsuyomu
金额：
$ 1.41万
依托单位：
Miyazaki Medical College
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1994
项目状态：
已结题

项目摘要

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.

我们首先利用彩色微球技术来测量胎儿组织中的血流，这导致了与放射性微球方法相似的模式。因此，我们随后用这种彩色微球法测定了缺氧急性期胎羊模型的脑血流量，结果显示，在缺氧期间，中脑和髓质的血流量增加明显大于大脑皮质。随后，我们重点研究了新生儿（0.85妊娠）和早产儿（0.7妊娠）之间低氧血流分布的发展变化。在这一系列实验中，早产胎儿低氧血症期间的血流量增加与近足月胎儿几乎相似。一个例外是海马血流在早产儿比在近期增加。最后，我们研究了硫酸镁对低氧血症时低氧反应的影响，因为镁在临床实践中是常用的。该实验表明，与对照组相比，在镁输注下，大脑皮质、心脏和肾上腺的血流量的低氧性增加得以维持。有趣的是，我们还观察到镁在低氧血症时不会减慢胎儿心率或增加血压。总之，彩色微球法可以测量胎儿血流量。利用这一点，我们已经表明，低氧变化的血流分布基本上是维持在早产儿和胎儿镁管理。