Yilmaz Cuneyt, Johnson Robert L, Hsia Connie C W
Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9034, USA.
Respir Physiol Neurobiol. 2005 Apr 15;146(2-3):215-23. doi: 10.1016/j.resp.2004.12.010.
We developed a multiple gas rebreathing technique for measuring lung diffusing capacity (DL(CO)), lung volume (V(L)) and cardiac output simultaneously in conscious spontaneously breathing small animals. Lung volume was measured from the dilution of methane (CH4) or sulfur hexafluoride (SF6) and verified independently by a helium washout technique. Cardiac output and DL(CO) were estimated from the uptake of acetylene and carbon monoxide, respectively. We tested guinea pigs at two levels of alveolar oxygen tension in order to estimate membrane diffusing capacity and pulmonary capillary blood volume by the Roughton-Forster technique. Results show that measured DL(CO) are consistent with reported values in anesthetized guinea pigs as well as with allometric comparison across species. Lung volume estimated from SF6 dilution agreed closely with that estimated independently from helium washout; however, lung volume estimated from CH4 dilution was systematically lower due to the addition of endogenously produced CH4 to the rebreathing system. We conclude that this technique can be used to measure resting lung function in conscious unsedated small animals.
我们开发了一种多气体再呼吸技术，用于在清醒、自主呼吸的小动物中同时测量肺弥散容量（DL(CO)）、肺容积（V(L)）和心输出量。通过甲烷（CH4）或六氟化硫（SF6）的稀释来测量肺容积，并通过氦气冲洗技术进行独立验证。心输出量和DL(CO)分别通过乙炔和一氧化碳的摄取来估算。我们在两种肺泡氧分压水平下对豚鼠进行了测试，以便通过Roughton-Forster技术估算膜弥散容量和肺毛细血管血容量。结果表明，测得的DL(CO)与麻醉豚鼠的报告值以及跨物种的异速生长比较结果一致。通过SF6稀释估算的肺容积与通过氦气冲洗独立估算的结果非常吻合；然而，由于再呼吸系统中添加了内源性产生的CH4，通过CH4稀释估算的肺容积系统性地偏低。我们得出结论，该技术可用于测量清醒、未使用镇静剂的小动物的静息肺功能。
