Dynamics of the collateral pathways of canine lungs after flow interruption.
Dynamics of the collateral pathways of canine lungs after flow interruption.
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血流中断后犬肺侧支通路的动态。
DOI：
10.1152/jappl.1989.67.3.1213
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Fredberg,JJ
中科院分区：
文献类型：
--
作者：
Ludwig,MS;Bellofiore,S;Shore,SA;Drazen,JM;Fredberg,JJ
在中断通过支气管镜输送到肺的楔形段中的恒定流量（Vcoll）之后，支气管镜尖端处的压力（Pb）通常以似乎指示两个时间常数的模式衰减。我们测试了以下假设：衰减的初始更快分量与跨支气管阻力（Rb）的压力平衡相关，将支气管镜尖端与肺泡分离，而较慢分量与跨侧支通路的压力平衡相关，将楔形段与周围区域分离。在8只开胸杂种犬中，我们将肺泡胶囊固定在楔形支气管镜对向的节段上，并在将Vcoll输送到节段中和突然中断后测量肺泡压力（PA）和Pb。在这两种控制条件下，并在输送雾化组胺（1.0或10毫克/毫升），我们无法证明铅和PA之间的梯度，无论是在恒定流量或流量中断后。当Pb的衰减不是单指数时，PA也不是。因此，没有证据表明存在明显的Rb，衰变的快速成分必须归因于其他因素。在第二个协议中，我们研究了行为偏离单指数衰减是否可归因于楔形段内的多室行为的存在，或者更确切地说，反映了一个单一的均匀的，但非线性室的行为。在5只闭胸犬中，我们通过改变Vcoll系统地改变了初始Pb，并记录了血流中断后的非指数压力衰减。（250字处删节）
After interruption of a constant flow (Vcoll) delivered through a bronchoscope into a wedged segment of lung, the pressure at the tip of the bronchoscope (Pb) often decays in a pattern seemingly indicative of two time constants. We tested the hypothesis that the initial more rapid component of the decay is associated with pressure equilibration across the bronchial resistance (Rb), separating bronchoscope tip from alveolus, and that the slower component is associated with pressure equilibration across the collateral pathways separating the wedged segment from surrounding regions. In eight open-chest mongrel dogs, we affixed an alveolar capsule to the segment subtended by the wedged bronchoscope and measured alveolar pressure (PA) and Pb during delivery of Vcoll into the segment and after its sudden interruption. Under both control conditions and after delivery of aerosolized histamine (1.0 or 10 mg/ml), we were unable to demonstrate a gradient between Pb and PA either during constant flow or after flow interruption. Whenever the decay of Pb was not monoexponential, neither was that of PA. Thus there was no evidence of an appreciable Rb, and the rapid component of the decay must be attributable to other factors. In a second protocol, we examined whether behavior departing from monoexponential decay was attributable to the presence of multicompartment behavior within the wedged segment or rather reflected the behavior of a single homogeneous but nonlinear compartment. In five closed-chest dogs, we systematically varied the initial Pb by changing Vcoll and recorded nonexponential pressure decay after flow interruption.(ABSTRACT TRUNCATED AT 250 WORDS)