Crackles and Wheezes: Agents of Injury?

Mechanically perturbed cells respond in many possible ways: growth, remodeling, altered metabolism, modified gene expression, release of bioactive molecules, membrane rupture, tissue failure, and death. Examining the soft palate tissue, it was shown that vibration significantly increased the gene expression of the proinflammatory cytokine TNF-α (tumor necrosis factor-α) and neutrophil attractant chemokine MIP-2 (macrophage inflammatory protein-2), which is a rodent equivalent of human IL-8. Histologic indexes of bronchiolar injury were present, but not in an additional group that received a tracheally instilled surfactant. Because the airways are liquid lined, closure is ultimately due to a liquid plug formation, made easier for decreasing airway radius or collapse during expiration. [...]they are protective for this kind of reopening injury.