Bernard Susan, Luchtel Dan L, Polissar Nayak, Hlastala Michael P, Lakshminarayan S
Department of Pulmonary and Critical Care Medicine, University of Washington School of Medicine and VA Medical Center, Seattle, Washington 98195, USA.
Anat Rec A Discov Mol Cell Evol Biol. 2005 Sep;286(1):804-13. doi: 10.1002/ar.a.20216.
The distribution and drainage of bronchial arterial blood flow are complex. We used two different methods to study the bronchial-pulmonary anastomoses in sheep lung. Initially, we injected two different sizes of fluorescent microspheres (15 and 100 microm diameter) into the bronchial artery and histologically determined where the different-size microspheres were entrapped in the lung. In a second series of animals, we injected Microfil into the bronchial artery to observe the anastomotic vessels. The microsphere data confirmed the existence of bronchial-to-pulmonary anastomoses. No microspheres were found in the systemic organs (heart and kidney), confirming the absence of large bronchial artery-to-pulmonary vein anastomoses. Unexpectedly, proportionately more large microspheres (100 microm) lodged in the alveolar parenchyma when compared to 15 microm microspheres. This suggests that there are many more small bronchial (< 100 microm) arterioles feeding the airway mucosa than the larger anastomotic vessels feeding into the parenchyma. In the Microfil cast lungs, we observed four types of anastomotic vessels: bronchial arteries/arterioles that anastomose with pulmonary arteries/arterioles that accompany airways; bronchial arterioles that anastomose directly with parenchymal (and eventually alveolar) vessels; bronchial arterioles that anastomose with blood vessels that do not accompany airways; and bronchial arterioles that anastomose with bronchial veins. Based on our in vivo microsphere data, the vessels that do not accompany the airways are most likely bronchial venules, not pulmonary venules.
支气管动脉血流的分布和引流较为复杂。我们采用两种不同方法研究绵羊肺内的支气管 - 肺吻合情况。首先，我们将两种不同大小的荧光微球（直径15和100微米）注入支气管动脉，并通过组织学方法确定不同大小的微球在肺内的滞留位置。在第二组动物实验中，我们将微显影剂注入支气管动脉以观察吻合血管。微球数据证实了支气管 - 肺吻合的存在。在体循环器官（心脏和肾脏）中未发现微球，证实不存在大的支气管动脉 - 肺静脉吻合。出乎意料的是，与15微米的微球相比，比例上更多的大微球（100微米）滞留在肺泡实质中。这表明，为气道黏膜供血的小支气管（<100微米）小动脉比为实质供血的较大吻合血管更多。在微显影剂铸型肺中，我们观察到四种类型的吻合血管：与伴行气道的肺动脉/小动脉吻合的支气管动脉/小动脉；直接与实质（最终为肺泡）血管吻合的支气管小动脉；与不伴行气道的血管吻合的支气管小动脉；以及与支气管静脉吻合的支气管小动脉。根据我们的体内微球数据，不伴行气道的血管很可能是支气管小静脉，而非肺小静脉。
