Becker P M, Pearse D B, Permutt S, Sylvester J T
Division of Pulmonary and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland 21224.
J Appl Physiol (1985). 1992 Dec;73(6):2616-22. doi: 10.1152/jappl.1992.73.6.2616.
In systemic organs, ischemia-reperfusion injury is thought to occur during reperfusion, when oxygen is reintroduced to hypoxic ischemic tissue. In contrast, the ventilated lung may be more susceptible to injury during ischemia, before reperfusion, because oxygen tension will be high during ischemia and decrease with reperfusion. To evaluate this possibility, we compared the effects of hyperoxic ischemia alone and hyperoxic ischemia with normoxic reperfusion on vascular permeability in isolated ferret lungs. Permeability was estimated by measurement of filtration coefficient (Kf) and osmotic reflection coefficient for albumin (sigma alb), using methods that did not require reperfusion to make these measurements. Kf and sigma alb in control lungs (n = 5), which were ventilated with 14% O2-5% CO2 after minimal (15 +/- 1 min) ischemia, averaged 0.033 +/- 0.004 g.min-1.mmHg-1.100 g-1 and 0.69 +/- 0.07, respectively. These values did not differ from those reported in normal in vivo lungs of other species. The effects of short (54 +/- 9 min, n = 10) and long (180 min, n = 7) ischemia were evaluated in lungs ventilated with 95% O2-5% CO2. Kf and sigma alb did not change after short ischemia (Kf = 0.051 +/- 0.006 g.min-1.mmHg-1.100 g-1, sigma alb = 0.69 +/- 0.07) but increased significantly after long ischemia (Kf = 0.233 +/- 0.049 g.min-1 x mmHg-1 x 100 g-1, sigma alb = 0.36 +/- 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
在全身器官中，缺血再灌注损伤被认为发生在再灌注期间，即向缺氧缺血组织重新供氧时。相比之下，通气的肺在缺血期间、再灌注之前可能更容易受到损伤，因为缺血期间氧张力会升高，而再灌注时会降低。为了评估这种可能性，我们比较了单纯高氧缺血以及高氧缺血后常氧再灌注对离体雪貂肺血管通透性的影响。通过测量滤过系数（Kf）和白蛋白的渗透反射系数（σalb）来估算通透性，所采用的方法无需再灌注即可进行这些测量。对照组肺（n = 5）在短暂（15 ± 1分钟）缺血后用14% O₂ - 5% CO₂通气，其Kf和σalb平均值分别为0.033 ± 0.004 g·min⁻¹·mmHg⁻¹·100 g⁻¹和0.69 ± 0.07。这些值与其他物种正常体内肺所报道的值无差异。在用95% O₂ - 5% CO₂通气的肺中评估了短时间（54 ± 9分钟，n = 10）和长时间（180分钟，n = 7）缺血的影响。短时间缺血后Kf和σalb没有变化（Kf = 0.051 ± 0.006 g·min⁻¹·mmHg⁻¹·100 g⁻¹，σalb = 0.69 ± 0.07），但长时间缺血后显著增加（Kf = 0.233 ± 0.049 g·min⁻¹·mmHg⁻¹·100 g⁻¹，σalb = 0.36 ± 0.05）。（摘要截取自250字）
