Hales C A, Rouse E T, Slate J L
J Appl Physiol Respir Environ Exerc Physiol. 1978 Jul;45(1):33-9. doi: 10.1152/jappl.1978.45.1.33.
Alveolar hypoxia induces pulmonary vasoconstriction but the strength of alveolar hypoxic vasoconstriction (AHV) is variable even within the same species. The influence of aspirin and indomethacin, cyclo-oxygenase inhibitors, was examined in two groups of dogs, those with weak AHV and those with vigorous AHV. A double-lumen endotracheal tube allowed ventilation of one lung with nitrogen as an alveolar hypoxic stimulus and ventilation of the other lung with O2 to maintain systemic oxygenation. Perfusion to each lung was measured with xenon-133 and external counters. In weak reactors both aspirin and indomethacin induced fourfold enhancement of AHV (P less than 0.01), whereas no significant influence on vigorous reactors was noted. Cyclo-oxygenase inhibitors also produced enhanced reactivity in the isolated lung to alveolar hypoxia and prostaglandin F2alpha but not to angiotensin II and norepinephrine. Aspirin-enhanced AHV in the isolated lung could not be diminished with blockade of angiotensin II receptors or of alpha receptors. In summary, weak AHV in intact or isolated dog lung may be due to an excess of a prostaglandin or prostacyclin vasodilator.
肺泡低氧可诱发肺血管收缩，但即使在同一物种内，肺泡低氧性血管收缩（AHV）的强度也存在差异。在两组犬中研究了环氧化酶抑制剂阿司匹林和吲哚美辛的影响，一组是AHV较弱的犬，另一组是AHV较强的犬。使用双腔气管导管，以氮气作为肺泡低氧刺激对一侧肺进行通气，以氧气对另一侧肺进行通气以维持全身氧合。用氙 - 133和外部计数器测量每侧肺的灌注。在反应较弱的犬中，阿司匹林和吲哚美辛均使AHV增强了四倍（P<0.01），而对反应较强的犬未观察到显著影响。环氧化酶抑制剂还使离体肺对肺泡低氧和前列腺素F2α的反应性增强，但对血管紧张素II和去甲肾上腺素无此作用。在离体肺中，阿司匹林增强的AHV不会因血管紧张素II受体或α受体的阻断而减弱。总之，完整或离体犬肺中较弱的AHV可能是由于前列腺素或前列环素血管舒张剂过量所致。
