Blosser S, Mitzner W, Wagner E M
Division of Pulmonary and Critical Care Medicine and Physiology, Johns Hopkins University, Baltimore, Maryland 21224.
J Appl Physiol (1985). 1994 Apr;76(4):1624-9. doi: 10.1152/jappl.1994.76.4.1624.
It has been suggested that airway obstruction may be mediated in part by airway vascular engorgement or airway wall edema. However, there are few data that support this conjecture. In this study we examined the effects of increased bronchial blood flow (Qba) on airway wall dimensions, conducting airway resistance, peripheral airway resistance, and airway reactivity assessed by methacholine aerosol challenge. The bronchial artery was perfused with autologous blood (control Qba = 0.6 ml.min-1.kg-1) in anesthetized ventilated sheep. The artery was perfused at either control (C) Qba or at high (H) Qba (300% of C Qba) for 3 h. Morphometry showed a doubling of the vascular area in airways exposed to H Qba (n = 4) compared with C Qba (n = 4). However, the significant increase in wall area could be accounted for only partially by the vascular changes, with edema fluid accumulation accounting for the major increase. Despite these changes, baseline airway resistance (n = 16) and peripheral airway resistance were both unaltered. Airway reactivity to methacholine before and after H Qba was also examined (n = 12). The 3 h of H Qba had no effect on airway reactivity regardless of whether challenge occurred with C or H Qba. The lack of effect of vascular engorgement on airway resistance or reactivity does not support a primary role for these factors in mediating airway obstruction.
有人提出气道阻塞可能部分由气道血管充血或气道壁水肿介导。然而，几乎没有数据支持这一推测。在本研究中，我们通过乙酰甲胆碱气雾剂激发试验，研究了支气管血流量增加（Qba）对气道壁尺寸、传导气道阻力、外周气道阻力和气道反应性的影响。在麻醉通气的绵羊中，用自体血液灌注支气管动脉（对照Qba = 0.6 ml·min⁻¹·kg⁻¹）。动脉以对照（C）Qba或高（H）Qba（C Qba的300%）灌注3小时。形态计量学显示，与C Qba（n = 4）相比，暴露于H Qba的气道（n = 4）中血管面积增加了一倍。然而，壁面积的显著增加仅部分可由血管变化解释，水肿液积聚是主要增加原因。尽管有这些变化，基线气道阻力（n = 16）和外周气道阻力均未改变。还检查了H Qba前后气道对乙酰甲胆碱的反应性（n = 12）。无论激发是用C Qba还是H Qba进行，3小时的H Qba对气道反应性均无影响。血管充血对气道阻力或反应性缺乏影响，不支持这些因素在介导气道阻塞中起主要作用。
