Mapping cyclic stretch in the postpneumonectomy murine lung

J Appl Physiol (1985). 2013 Nov 1;115(9):1370-8. doi: 10.1152/japplphysiol.00635.2013. Epub 2013 Aug 29.


In many mammalian species, the removal of one lung [pneumonectomy (PNX)] is associated with the compensatory growth of the remaining lung. To investigate the hypothesis that parenchymal deformation may trigger lung regeneration, we used respiratory-gated micro-computed tomography scanning to create three-dimensional finite-element geometric models of the murine cardiac lobe with cyclic breathing. Models were constructed of respiratory-gated micro-computed tomography scans pre-PNX and 24 h post-PNX. The computational models demonstrated that the maximum stretch ratio map was patchy and heterogeneous, particularly in subpleural, juxta-diaphragmatic, and cephalad regions of the lobe. In these parenchymal regions, the material line segments at peak inspiration were frequently two- to fourfold greater after PNX; some regions of the post-PNX cardiac lobe demonstrated parenchymal compression at peak inspiration. Similarly, analyses of parenchymal maximum shear strain demonstrated heterogeneous regions of mechanical stress with focal regions demonstrating a threefold increase in shear strain after PNX. Consistent with previously identified growth patterns, these subpleural regions of enhanced stretch and shear strain are compatible with a mechanical signal, likely involving cyclic parenchymal stretch, triggering lung growth.

Keywords: finite element; image registration; lung; pneumonectomy; regeneration.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Lung / physiology*
  • Lung Volume Measurements / methods
  • Mice
  • Mice, Inbred C57BL
  • Pneumonectomy / methods
  • Regeneration / physiology*
  • Respiration
  • Stress, Mechanical
  • Tomography, X-Ray Computed / methods