Age-dependent changes in the postnatal intestinal microcirculation.
Age-dependent changes in the postnatal intestinal microcirculation.
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产后肠道微循环的年龄依赖性变化。
DOI：
10.1038/sj/mn/7800110
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Nowicki,PT
中科院分区：
文献类型：
--
作者：
Nankervis,CA;Reber,KM;Nowicki,PT
在从胎儿到新生儿的过渡期以及出生后的第一个月内，肠道血液动力学发生了显著变化。最重要的是，基础血管阻力在出生后大幅下降。然后在出生后第1天和第3天之间进一步降低，达到平台期，然后在出生后第12天和第30天之间开始缓慢，渐进的增加。肠血流的基础速率以相反的方式反映血管阻力的变化。出生后的血管阻力的变化似乎是介导的，在很大程度上，由一氧化氮的组成和刺激生产的增加。最重要的是，新生儿终末肠系膜动脉的直径（直径150-300 µm）（即，1日龄）猪的生长是由三种内在的血管控制系统决定的：内皮细胞产生一氧化氮和内皮素，以及血管平滑肌的内在肌源性反应。相比之下，老年受试者中的这些血管（即，35日龄）本质上主要是被动的，并且不能显示响应于内源性一氧化氮产生或内皮素受体的阻断或施加的压力或流速扰动的显著直径变化。与成人情况相比，围产期和新生儿肠道的循环生理学异常，因为胎儿和新生儿生命之间以及出生后第一个月期间的几个血流动力学变量变化非常显著。围产期和新生儿肠道特有的血液动力学状况似乎是胎儿出生后用胃肠道取代胎盘以获得营养的整体生理转变的一部分。这篇综述的目的是描述围产期和新生儿肠道的循环生理学，特别强调迄今为止已经研究过的肠道微循环的那些部分。然而，首先，重要的是要讨论在围产期和新生儿早期肠循环中发生的年龄依赖性变化。
Significant changes occur in intestinal hemodynamics during the transition from fetal to newborn life and then again during the first postnatal month. Most importantly, basal vascular resistance substantially decreases following birth. It then decreases further between postnatal days 1 and 3, plateaus, and then begins a slow, progressive increase between postnatal days 12 and 30. The basal rate of intestinal blood flow mirrors the changes in vascular resistance in an inverse manner. The postnatal changes in vascular resistance appear to be mediated, in large part, by an increase in the constitutive and stimulated production of nitric oxide. Most importantly, the diameter of terminal mesenteric arteries (150–300 µm diameter) in newborn (i.e., 1 day old) swine is determined by three intrinsic vascular control systems: endothelial production of nitric oxide and endothelin, and the inherent myogenic response of vascular smooth muscle. In contrast, these vessels in older subjects (i.e., 35 days old) are primarily passive in nature and fail to demonstrate significant diameter change in response to blockade of endogenous nitric oxide production or endothelin receptors, or applied perturbations of pressure or flow rate. The circulatory physiology of the perinatal and newborn intestine is exceptional when compared to the adult condition inasmuch as several hemodynamic variables change quite dramatically between fetal and neonatal life and during the first postnatal month. The unique hemodynamic conditions that characterize the perinatal and newborn intestine appear to be part of the overall physiological transition that occurs as the fetus, once born, replaces the placenta with his gastrointestinal tract to obtain nutrition. The goal of this review is to describe the circulatory physiology of the perinatal and newborn intestine, with a particular emphasis on those portions of the intestinal microcirculation that have thus far been studied. First, however, it is important to discuss the age-dependent changes that occur within the intestinal circulation during perinatal and early newborn life.Microcirculation (2001) 8, 377–387.