Abstract
To examine the effects of mechanical lung strain on regenerative growth of alveolar septal tissue after pneumonectomy (PNX), we replaced the right lungs of adult dogs with a custom-shaped inflatable silicone prosthesis. The prosthesis was either inflated (Inf) to maintain the mediastinum at the midline or deflated to allow mediastinal shift. The animals were euthanized ∼ 15 mo later, and the lungs were fixed at a constant distending pressure. With the Inf prostheses, lung expansion, alveolar septal tissue volumes, surface areas, and diffusing capacity of the tissue-plasma barrier were significantly lower than with the deflated prostheses; the expected post-PNX tissue responses were impaired by 30-60%. Capillary blood volume was significantly higher with Inf prostheses, consistent with microvascular congestion. Measurements in the Inf group remained consistently and significantly higher than those expected for a normal left lung, indicating persistence of partial compensation. In one dog, delayed deflation of the prosthesis 9-10 mo after PNX led to vigorous lung expansion and septal tissue growth, particularly of type II epithelial cells. We conclude that mechanical lung strain is a major signal for regenerative lung growth; however, other signals are also implicated, accounting for a significant fraction of the compensatory response to PNX.
Original language | English (US) |
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Pages (from-to) | L1279-L1287 |
Journal | American Journal of Physiology - Lung Cellular and Molecular Physiology |
Volume | 281 |
Issue number | 5 25-5 |
DOIs | |
State | Published - 2001 |
Keywords
- Compensatory lung growth
- Diffusing capacity
- Dog
- Lung resection
- Lung strain
- Mechanical strain
- Mechanical stretch
- Morphometry
ASJC Scopus subject areas
- Physiology
- Pulmonary and Respiratory Medicine
- Physiology (medical)
- Cell Biology