title: Mapping cyclic stretch in the postpneumonectomy murine lung.
abstract: 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.
authors.affiliation: Faculty of Engineering, University of Kragujevac, Kragujevac, Serbia;
authors.forename: Nenad
authors.initials: N
authors.lastname: Filipovic
authors.forename: Barry C
authors.initials: BC
authors.lastname: Gibney
authors.forename: Milos
authors.initials: M
authors.lastname: Kojic
authors.forename: Dalibor
authors.initials: D
authors.lastname: Nikolic
authors.forename: Velibor
authors.initials: V
authors.lastname: Isailovic
authors.forename: Alexandra
authors.initials: A
authors.lastname: Ysasi
authors.forename: Moritz A
authors.initials: MA
authors.lastname: Konerding
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Mentzer
authors.forename: Akira
authors.initials: A
authors.lastname: Tsuda
mesh_terms: D000818:Animals; D008168:Lung / Q000502:physiology*; D008176:Lung Volume Measurements / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D011013:Pneumonectomy / Q000379:methods; D012038:Regeneration / Q000502:physiology*; D012119:Respiration; D013314:Stress, Mechanical; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: finite element; image registration; lung; pneumonectomy; regeneration