alpha-Actin: disposition, quantities, and estimated effects on lung recoil and compliance
2001 (English)In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 91, no 1, 459-473 p.Article in journal (Refereed) Published
We have investigated the basis and implications of pneumoconstriction by measuring disposition and quantities of alpha -smooth muscle actin in rat and guinea pig lungs and modeling its effects on lung recoil and compliance. A robust marker of contractility, alpha -smooth muscle actin appears in smooth muscle or myofibroblast-like cells in pleura, airways, blood vessels, and alveolar ductal tissues. In each site, we measured its transected area by immunofluorescent staining and frequency-modulated scanning confocal microscopy. We incorporated these data in a model of the parenchyma consisting of an extensive elastic network with embedded contractile structures. We conclude that contraction at any one of these sites alone can decrease parenchymal compliance by 20-30% during tidal breathing. This is due mostly to the stiffness of activated contractile elements undergoing passive cycling; constant muscle tension would have little effect. The magnitude of the effect corresponds with known responses of the lung to hypocapnia, consistent with a homeostatic function in which gas exchange is defended by redistributing ventilation away from overventilated units.
Place, publisher, year, edition, pages
2001. Vol. 91, no 1, 459-473 p.
alveolar duct, intensity-modulated multiple-wavelength, scanning confocal microscopy, lung compliance, ventilation-perfusion ratio, hypocapnia, airway smooth-muscle, ventilation distribution, interstitial-cells, alveolar septa, dog lungs, rat lung, tissue, mechanics, constriction, volume
IdentifiersURN: urn:nbn:se:kth:diva-20735ISI: 000169471700059OAI: oai:DiVA.org:kth-20735DiVA: diva2:339432
QC 201005252010-08-102010-08-10Bibliographically approved