Garcia M L, Paiva P S, Dolhnikoff M, Jancar S, Saldiva P H, Martins M A
Departamento de Patologia, Faculdade de Medicina, Universidade de São Paulo, Brazil.
Exp Lung Res. 1994 May-Jun;20(3):169-84. doi: 10.3109/01902149409064381.
We studied airway and pulmonary tissue responses to platelet-activating factor (PAF) in rats by measuring alveolar pressure with the alveolar capsule technique. We calculated airway resistance (Raw), dynamic elastance (Edyn), and pulmonary tissue resistance (Rtis). PAF was administered intravenously in doses of 0.1, 1, 10, and 30 micrograms (1 dose per animal, 5 rats for each dose). Infusion of PAF resulted in a significant increase in Rtis and Edyn (p < .05). Maximal values of Edyn were observed with the infusion of 10 micrograms of PAF (p < .02). Rtis presented a significant increase after infusion of 1 microgram of PAF (p < .05). The observed increase in Raw was transient and did not reach statistical significance. After infusion of PAF lungs were fixed by a quick-freezing method. Morphometric analysis showed that PAF infusion resulted in significant increases in intraluminal secretion (p = .001) and peribronchiolar edema (p < .001) but did not result in significant airway contraction. We conclude that intravenous infusion of PAF results in significant effects on lung tissue mechanics. The effects of PAF on the mechanical properties of lung parenchyma reflect the inflammatory alterations induced by this agonist in distal airspaces.
我们通过用肺泡囊技术测量肺泡压力，研究了大鼠气道和肺组织对血小板活化因子（PAF）的反应。我们计算了气道阻力（Raw）、动态弹性（Edyn）和肺组织阻力（Rtis）。以0.1、1、10和30微克的剂量静脉注射PAF（每只动物1剂，每个剂量5只大鼠）。PAF输注导致Rtis和Edyn显著增加（p < .05）。输注10微克PAF时观察到Edyn的最大值（p < .02）。输注1微克PAF后Rtis显著增加（p < .05）。观察到的Raw增加是短暂的，未达到统计学意义。输注PAF后，通过快速冷冻法固定肺。形态计量学分析表明，PAF输注导致管腔内分泌显著增加（p = .001）和细支气管周围水肿显著增加（p < .001），但未导致显著的气道收缩。我们得出结论，静脉输注PAF对肺组织力学有显著影响。PAF对肺实质力学特性的影响反映了该激动剂在远端气腔中诱导的炎症改变。
