Duane S F, Weir E K, Stewart R M, Niewoehner D E
Respir Physiol. 1979 Dec;38(3):303-11. doi: 10.1016/0034-5687(79)90056-2.
The reactivity of subpleural strips of lung parenchyma reflects primarily the tone of the smooth muscle in the peripheral airways. Lung strips taken from ten dogs relaxed when the oxygen level in the gas bubbling through the bath was reduced from 95% to 18%. Subsequent hypocapnia (carbon dioxide reduced from 5% to 0%) induced contraction of all strips. These changes were reversed when the oxygen or carbon dioxide tensions were restored to control levels. Addition of either indomethacin or meclofenamate, two chemically dissimilar inhibitors of prostaglandin synthetase, reduced the resting tone in each of six strips and prevented the hyperoxic constriction which was observed in paired, control strips (oxygen increased from 18% to 95%). Blockers of histamine and catecholamines had no effect. The reactivity of the distal airways to changes in gas tension provides a mechanism by which ventilation and perfusion can be matched. The action of indomethacin and meclofenamate indicates that a prostaglandin-like substance may be involved in the maintenance of distal airway tone and in the constriction produced by hyperoxia. The addition of prostaglandin F2 alpha or E1, after meclofenamate, in a further nine pairs of strips did not restore the hyperoxic constriction. This suggests that prostaglandins may mediate, rather than merely facilitate, the response.
肺实质胸膜下条带的反应性主要反映外周气道平滑肌的张力。当通过浴槽鼓泡的气体中的氧气水平从95%降至18%时，取自10只狗的肺条带会松弛。随后的低碳酸血症（二氧化碳从5%降至0%）会导致所有条带收缩。当氧气或二氧化碳张力恢复到对照水平时，这些变化会逆转。添加吲哚美辛或甲氯芬那酸这两种化学性质不同的前列腺素合成酶抑制剂，可降低6条肺条带中每条的静息张力，并阻止在配对的对照条带中观察到的高氧收缩（氧气从18%增加到95%）。组胺和儿茶酚胺的阻滞剂没有作用。远端气道对气体张力变化的反应性提供了一种使通气和灌注相匹配的机制。吲哚美辛和甲氯芬那酸的作用表明，一种前列腺素样物质可能参与远端气道张力的维持以及高氧引起的收缩。在另外9对条带中，在甲氯芬那酸之后添加前列腺素F2α或E1并没有恢复高氧收缩。这表明前列腺素可能介导而不仅仅是促进这种反应。
