O'Brodovich H, Coates G
J Appl Physiol (1985). 1986 Jan;60(1):38-44. doi: 10.1152/jappl.1986.60.1.38.
Experiments were performed to determine whether different methods of increasing cardiac output would have similar effects on lung lymph flow, and to assess the contribution of the microvasculature (fluid-exchanging vessels) to the total calculated pulmonary vascular resistance. Yearling unanesthetized sheep with chronic vascular catheters and lung lymph fistulas underwent intravenous infusions of isoproterenol at 0.2 micrograms X kg-1. min-1 (n = 8) or were exercised on a treadmill (n = 16). Both isoproterenol and exercise increased cardiac output, lowered calculated total pulmonary and systemic vascular resistances, and had no effect on the calculated pulmonary microvascular pressure. Isoproterenol infusions did not affect lung lymph flow, whereas exercise increased lung lymph flow in proportion to the increase in cardiac output. We conclude that 1) the sheep has a different pulmonary hemodynamic response to exercise than dogs and man, 2) the microvasculature is recruited during exercise-induced but not isoproterenol-induced increases in cardiac output, and 3) the microvasculature represents only a small proportion of the total calculated pulmonary vascular resistance.
进行实验以确定增加心输出量的不同方法是否会对肺淋巴流量产生相似的影响，并评估微血管（液体交换血管）对计算出的总肺血管阻力的贡献。对带有慢性血管导管和肺淋巴瘘的一岁未麻醉绵羊，以0.2微克×千克⁻¹·分钟⁻¹的剂量静脉输注异丙肾上腺素（n = 8），或在跑步机上运动（n = 16）。异丙肾上腺素和运动均增加了心输出量，降低了计算出的总肺血管阻力和体循环血管阻力，且对计算出的肺微血管压力没有影响。输注异丙肾上腺素不影响肺淋巴流量，而运动使肺淋巴流量与心输出量的增加成比例增加。我们得出结论：1）绵羊对运动的肺血流动力学反应与狗和人不同；2）在运动诱导而非异丙肾上腺素诱导的心输出量增加过程中微血管被募集；3）微血管仅占计算出的总肺血管阻力的一小部分。
