Fetal chemoreception: a developing story.
Fetal chemoreception: a developing story.
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胎儿化学感受：一个发展中的故事。
DOI：
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发表时间：
1996
期刊：
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通讯作者：
D. Teitel
中科院分区：
文献类型：
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作者：
D. Teitel
中枢和外周化学感受器对于出生后有效摄取和输送氧气以及清除二氧化碳至关重要。然而，胎儿化学感受的重要性和活性受到质疑，因为氧气摄取和二氧化碳清除在胎儿肺部不受调节。早期的研究表明，化学传导-通过化学感受器刺激，神经传入活动和神经激素效应器机制的整合，化学刺激转化为心血管和呼吸反应-在其单个组件或它们的相互作用是不成熟的。然而，现在看来，化学感受器级联在晚期胎儿的结构和功能上是完整的，并积极响应正常和其他化学刺激。胎儿和出生后的化学转导之间的差异似乎主要取决于中枢抑制的反应，抑制区域被定位到侧脑桥。它似乎部分由胎盘因子介导，胎盘因子在出生时被去除，允许表达免疫反应。这种反应的抑制也是心率反应差异的原因：出生后的心动过速是由肺膨胀反射引起的;当消除时，心动过缓被观察到，就像胎儿一样。尽管化学感受的排泄成分受到抑制，胎儿颈动脉化学感受器比主动脉更重要，尽管它被认为对排泄比对心血管稳定更重要。这篇评论讨论了目前的知识成熟的化学感受器级联反应的各个组成部分，并提出了胎儿的故事在这个框架内。
The central and peripheral chemoreceptors are critical to the efficient uptake and delivery of oxygen and the removal of carbon dioxide after birth. However, the importance and activity of fetal chemoreception has been questioned, since oxygen uptake and carbon dioxide removal are not regulated in the lungs in the fetus. Early studies suggested that chemotransduction-the conversion of a chemical stimulus to cardiovascular and ventilatory responses via the integration of chemoreceptor stimulation, neural afferent activity and neurohormonal effector mechanisms-was immature in its individual components or their interaction. However, it now appears that the chemoreceptor cascade is structurally and functionally intact in the late-term fetus, and responds actively to normal and other chemical stimuli. The differences between fetal and postnatal chemotransduction appear to be primarily dependent on the central inhibition of the ventilatory response, the inhibitory area being localized to the lateral pons. It appears to be mediated in part by a placental factor which is removed at birth, allowing for the expression of the ventilatory response. The suppression of this response is also responsible for the difference in the heart rate response: the postnatal tachycardia is caused by the lung inflation reflex; when abolished, bradycardia is seen, just as in the fetus. Despite the suppression of the ventilatory component of chemoreception, the fetal carotid chemoreceptor is more important than the aortic, even though it has been considered to be more important to ventilatory than to cardiovascular stability. This review discusses current knowledge of the various components of the mature chemoreceptor cascade, and presents the fetal story within that framework.