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Title

Impact of microvascular circulation on peripheral lung stability

Authors
Hantos, Zoltan
Suki, Béla
Published in American Journal of Physiology. Lung Cellular and Molecular Physiology. 2004, vol. 287, no. 4, p. L879-89
Abstract The involvement of pulmonary circulation in the mechanical properties was studied in isolated rat lungs. Pulmonary input impedance (ZL) was measured at a mean transpulmonary pressure (Ptpmean) of 2 cmH2O before and after physiological perfusion with either blood or albumin. In these lungs and in a group of unperfused lungs, ZL was also measured at Ptpmean values between 1 and 8 cmH2O. Airway resistance (Raw) and parenchymal damping (G) and elastance (H) were estimated from ZL. End-expiratory lung volume (EELV) was measured by immersion before and after blood perfusion. The orientation of the elastin fibers relative to the basal membrane was assessed in additional unperfused and blood-perfused lungs. Pressurization of the pulmonary capillaries significantly decreased H by 31.5 +/- 3.7% and 18.7 +/- 2.7% for blood and albumin, respectively. Perfusion had no effect on Raw but markedly altered the Ptpmean dependences of G and H < 4 cmH2O, with significantly lower values than in the unperfused lungs. At a Ptpmean of 2 cmH2O, EELV increased by 31 +/- 11% (P = 0.01) following pressurization of the capillaries, and the elastin fibers became more parallel to the basal membrane. Because the organization of elastin fibers results in smaller H values of the individual alveolus, the higher H in the unperfused lungs is probably due to a partial alveolar collapse leading to a loss in lung volume. We conclude that the physiological pressure in the pulmonary capillaries is an important mechanical factor in the maintenance of the stability of the alveolar architecture.
Keywords AnimalsIn Vitro TechniquesLung/cytology/physiologyMaleMicrocirculation/physiologyPerfusion/methodsPulmonary Alveoli/blood supplyPulmonary Circulation/physiologyRatsRats, Sprague-DawleyRespiratory Function Tests
Identifiers
PMID: 15208092
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Article (Published version) (514 Kb) - public document Free access
Structures
Research groups Enfants et hyperréactivité bronchique (69)
Groupe Pache Jean-Claude (pathologie clinique) (658)
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(ISO format)
PETAK, Ferenc et al. Impact of microvascular circulation on peripheral lung stability. In: American Journal of Physiology. Lung Cellular and Molecular Physiology, 2004, vol. 287, n° 4, p. L879-89. https://archive-ouverte.unige.ch/unige:55493

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Deposited on : 2015-04-13

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