Mann C M, Domino K B, Walther S M, Glenny R W, Polissar N L, Hlastala M P
Department of Anesthesiology, University of Washington School of Medicine, Seattle, Washington 98195, USA.
J Appl Physiol (1985). 1998 Jun;84(6):2010-9. doi: 10.1152/jappl.1998.84.6.2010.
We used fluorescent-labeled microspheres in pentobarbital-anesthetized dogs to study the effects of unilateral alveolar hypoxia on the pulmonary blood flow distribution. The left lung was ventilated with inspired O2 fraction of 1.0, 0.09, or 0.03 in random order; the right lung was ventilated with inspired O2 fraction of 1.0. The lungs were removed, cleared of blood, dried at total lung capacity, then cubed to obtain approximately 1,500 small pieces of lung ( approximately 1.7 cm3). The coefficient of variation of flow increased (P < 0.001) in the hypoxic lung but was unchanged in the hyperoxic lung. Most (70-80%) variance in flow in the hyperoxic lung was attributable to structure, in contrast to only 30-40% of the variance in flow in the hypoxic lung (P < 0.001). When adjusted for the change in total flow to each lung, 90-95% of the variance in the hyperoxic lung was attributable to structure compared with 70-80% in the hypoxic lung (P < 0.001). The hilar-to-peripheral gradient, adjusted for change in total flow, decreased in the hypoxic lung (P = 0.005) but did not change in the hyperoxic lung. We conclude that hypoxic vasoconstriction alters the regional distribution of flow in the hypoxic, but not in the hyperoxic, lung.
我们在戊巴比妥麻醉的犬身上使用荧光标记微球，以研究单侧肺泡缺氧对肺血流分布的影响。左肺以吸入氧分数为1.0、0.09或0.03的顺序随机通气；右肺以吸入氧分数为1.0进行通气。取出肺脏，清除血液，在肺总量下干燥，然后切成小块以获得约1500块小肺组织（约1.7立方厘米）。缺氧肺中血流变异系数增加（P<0.001），而高氧肺中则无变化。高氧肺中大部分（70 - 80%）的血流变异归因于结构，相比之下缺氧肺中仅30 - 40%的血流变异归因于结构（P<0.001）。当根据每个肺的总血流变化进行调整后，高氧肺中90 - 95%的血流变异归因于结构，而缺氧肺中为70 - 80%（P<0.001）。经总血流变化调整后的肺门至周边梯度在缺氧肺中降低（P = 0.005），而在高氧肺中无变化。我们得出结论，缺氧性血管收缩改变了缺氧肺而非高氧肺中的血流区域分布。
