Whole body structural vascular adaptation to prolonged hypoxia in chick embryos.
Whole body structural vascular adaptation to prolonged hypoxia in chick embryos.
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鸡胚胎全身结构血管对长期缺氧的适应。
DOI：
10.1152/ajpheart.1987.252.6.h1228
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Stanek,KA
中科院分区：
文献类型：
--
作者：
Adair,TH;Guyton,AC;Montani,JP;Lindsay,HL;Stanek,KA
我们通过对鸡胚胎全身和后肢结构血管阻力的功能测量，研究了低氧在血管系统发育中的作用。这种方法是基于一种新开发的全身灌流技术，在这种技术中，14至15天的鸡胚胎的最大扩张血管通过胚外血管进行灌流。将胚胎在12%氧气(PO265 mm Hg，n=18)或16%氧气(Po296 mm Hg，n=19)中培养7d，并与体重匹配(n=17)和年龄匹配(n=18)的常氧对照组(PO2134 Mm Hg)进行比较。所有胚胎的压力-流量曲线都是通过在0-6毫米汞柱的压力范围内沿1-毫米汞阶梯增加和降低主动脉压来绘制的。通过切断胚外静脉使灌流液自由流出，将静脉压维持在0毫米汞柱。最大扩张血管床的水力阻力，称为“结构血管阻力”，在低氧组中以剂量相关的方式降低到全身和后肢12%氧气组对照的50%以上。与体重匹配的常氧对照组相比，12%氧气组的血管向全身和后肢组织输送的流量分别是对照组的两倍和三倍。因此，结果支持了这样的假设，即长期暴露在低氧环境中会导致血管系统调整其结构，以允许在任何给定的灌流压力梯度下有更多的血液流向组织。
We studied the role of hypoxia in the development of the blood vascular system using functional measurements of whole body and hindlimb structural vascular resistance in the chick embryo. The method is based on a newly developed whole body perfusion technique in which the maximally dilated blood vasculature of 14- to 15-day chick embryos is perfused through the extraembryonic blood vessels. Embryos were grown in 12% oxygen (Po2 65 mmHg, n = 18) or 16% oxygen (Po2 96 mmHg, n = 19) for the last 7 days of incubation and were compared with weight-matched (n = 17) and age-matched (n = 18) normoxic control groups (Po2 134 mmHg). Pressure-flow curves were generated for all embryos by increasing and decreasing the aortic pressure along 1-mmHg steps over a pressure range of 0-6 mmHg. Venous pressure was held at 0 mmHg by allowing the perfusate to flow freely from severed extraembryonic veins. The hydraulic resistance of the maximally dilated vascular bed, called the "structural vascular resistance," was decreased in a dose-related manner in the hypoxic groups to greater than 50% of control in the whole body and hindlimbs of the 12% oxygen group. The vessels of the 12% oxygen group were able to carry two and three times as much flow to the whole body and hindlimb tissues, respectively, as compared with the weight-matched normoxic control group. Therefore, the results support the hypothesis that prolonged exposure to hypoxia causes the blood vascular system to adapt its structure to allow greater amounts of blood to flow to the tissues at any given perfusion pressure gradient.