Qiao R L, Sadurski R, Bhattacharya J
Department of Medicine, College of Physicians and Surgeons, Columbia University, St. Luke's-Roosevelt Hospital Center, New York, New York 10019.
Am J Physiol. 1993 Apr;264(4 Pt 1):L382-6. doi: 10.1152/ajplung.1993.264.4.L382.
We report the first determination of lung endothelial barrier properties in ischemic, nonreperfused microvessels. We quantified the endothelial barrier in terms of hydraulic conductivity (Lp) in single pulmonary venules (diameter 20-50 microns) of isolated blood perfused lungs (dog, rat), held at constant inflation pressure (5 cmH2O) with a gas mixture containing 21% oxygen. Lp were determined by our split-drop technique in which an oil drop is first microinjected into a venule and then split by microinjection of a protein solution. Lp was interpreted from measurements of the rate of oil drop movement. Baseline Lp recorded in the first 30 min of perfusion averaged 3.4 +/- 0.9 x 10(-7) ml/(cm2.s.cmH2O). Then, in two separate groups of venules in which we established 1.3 +/- 0.1 h and 3.4 +/- 0.8 h of ischemia, we determined Lp which were, respectively, 145 +/- 6.5 and 308 +/- 13% above baseline (P < 0.05). We conclude that ischemia alone, in the absence of reperfusion, significantly deteriorates the lung endothelial barrier.
我们报告了首次对缺血、未再灌注微血管中肺内皮屏障特性的测定。我们通过水力传导率（Lp）对分离的血液灌注肺（犬、大鼠）中直径为20 - 50微米的单个肺小静脉的内皮屏障进行了量化，这些肺在含有21%氧气的气体混合物中保持恒定充气压力（5 cmH₂O）。Lp通过我们的分滴技术测定，即先将油滴显微注射到小静脉中，然后通过显微注射蛋白质溶液将其分开。Lp根据油滴移动速率的测量结果进行解读。灌注最初30分钟记录的基线Lp平均为3.4 ± 0.9×10⁻⁷ ml/(cm²·s·cmH₂O)。然后，在两组分别建立了1.3 ± 0.1小时和3.4 ± 0.8小时缺血时间的小静脉中，我们测定的Lp分别比基线高145 ± 6.5%和308 ± 13%（P < 0.05）。我们得出结论，在没有再灌注的情况下，单纯缺血会显著损害肺内皮屏障。
