Milstein J M, Goetzman B W
Am J Cardiol. 1985 Oct 1;56(10):681-4. doi: 10.1016/0002-9149(85)91035-5.
Balloon distention of the left pulmonary artery (PA) was produced in 14 lambs (aged 1 to 3 days) to assess whether an increase in systemic vascular resistance results from such distention. The lambs were anesthetized with chloralose and instrumented to enable measurement of systemic blood flow, PA pressure, aortic pressure, heart rate and right atrial pressure. PA distention resulted in an increase in systemic vascular resistance and aortic pressure (p less than 0.05). This result was probably due to a systemic vasoconstrictor response, since systemic blood flow and right atrial pressure did not change significantly. Limited trials using autonomic blocking agents suggested that the response is either a reflex under autonomic control or a response to humoral release of alpha-adrenergic substances. In conclusion, some interdependence appears to exist between the systemic and pulmonary vascular beds. It is postulated that such changes may be important in fetal life when they may affect redistribution of cardiac output during adaptation to hypoxemia.
对14只1至3日龄的羔羊进行左肺动脉球囊扩张，以评估这种扩张是否会导致体循环血管阻力增加。用氯醛糖对羔羊进行麻醉，并安装仪器以测量体循环血流量、肺动脉压、主动脉压、心率和右心房压。肺动脉扩张导致体循环血管阻力和主动脉压增加（p<0.05）。这一结果可能是由于全身血管收缩反应，因为体循环血流量和右心房压没有明显变化。使用自主神经阻滞剂的有限试验表明，该反应要么是自主神经控制下的反射，要么是对α-肾上腺素能物质体液释放的反应。总之，体循环和肺循环血管床之间似乎存在某种相互依存关系。据推测，这种变化在胎儿期可能很重要，因为它们可能会影响适应低氧血症时的心输出量重新分配。
