Mathieu-Costello O, Willford D C, Fu Z, Garden R M, West J B
Department of Medicine, University of California, San Diego, La Jolla 92093-0623, USA.
J Appl Physiol (1985). 1995 Sep;79(3):908-17. doi: 10.1152/jappl.1995.79.3.908.
We previously showed that stress failure of pulmonary capillaries occurs at transmural pressures of approximately 50 cmH2O (40 mmHg) and above in rabbit lung. In this study, we examined whether pulmonary capillaries are more resistant to failure in dogs than in rabbits. This might be expected because of the greater athletic ability of dogs and therefore their presumably greater tolerance to large cardiac outputs and higher pulmonary vascular pressures. The lungs of 12 anesthetized mongrel dogs [22.1 +/- 5.2 (SD) kg] were perfused in situ with autologous blood and then with saline-dextran (5 min) and glutaraldehyde solution (10 min), all three perfusions at the same preset transmural pressure of 32.5, 72.5, 92.5, or 112.5 cmH2O. In dogs, the stress failure curves relating break number per millimeter of epithelium and endothelium were right shifted by approximately 40 cmH2O compared with rabbits. Blood-gas barrier thickness was significantly greater than in rabbits at 32.5 cmH2O, and unlike in rabbits, neither total nor interstitial thickness increased significantly with increasing pressure. These results indicate that pulmonary capillaries are more resistant to stress failure in dogs than rabbits.
我们之前的研究表明，兔肺中肺毛细血管在跨壁压约为50 cmH₂O（40 mmHg）及以上时会发生应力性破裂。在本研究中，我们检测了犬肺毛细血管是否比兔肺毛细血管更耐受破裂。鉴于犬具有更强的运动能力，因此推测它们对大量心输出量和更高肺血管压力可能具有更高的耐受性，出现这种情况是可以预料的。对12只麻醉的杂种犬（体重22.1±5.2（标准差）kg）的肺进行原位自体血液灌注，然后依次用生理盐水 - 葡聚糖（5分钟）和戊二醛溶液（10分钟）灌注，所有这三种灌注均在32.5、72.5、92.5或112.5 cmH₂O的相同预设跨壁压下进行。与兔相比，犬的上皮和内皮每毫米破裂数的应力性破裂曲线右移约40 cmH₂O。在32.5 cmH₂O时，血气屏障厚度显著大于兔，并且与兔不同的是，总厚度和间质厚度均不会随压力增加而显著增加。这些结果表明，犬肺毛细血管比兔肺毛细血管更耐受应力性破裂。
