Vol. 92, Issue 1, 230-234, January 2002
Comparison of rat and mouse pulmonary tissue mechanical
properties and histology
Débora S.
Faffe1,
Patricia R. M.
Rocco1,
Elnara M.
Negri2, and
Walter A.
Zin1
1 Laboratory of Respiration Physiology, Carlos Chagas Filho
Biophysics Institute, Federal University of Rio de Janeiro, Ilha do
Fundão, 21949-900, Rio de Janeiro; and 2 Department of
Clinical Emergencies and Department of Pathology, University of
São Paulo, 01246-000 São Paulo, Brazil
The present
study compares the dynamic mechanical properties and the contents
of collagen and elastic fibers (oxytalan + elaunin + fully
developed elastic fibers) of mice and rat lung strips.
Resistance, elastance (E), and hysteresivity (
) were obtained during
sinusoidal oscillations. The relative amounts of blood vessel,
bronchial, and alveolar walls, as well as the mean alveolar diameter
were determined. In both species, resistance had a negative and E a
positive dependence on frequency, whereas remained unchanged. Mice
showed higher E and lower than rats. Although collagen and elastic
fiber contents were similar in both groups, mice had more oxytalan and
less elaunin and fully developed elastic fibers than rats. Rats showed
less alveolar and more blood vessel walls and higher mean alveolar
diameter than mice. In conclusion, mice and rats present distinct
tissue mechanical properties, which are accompanied by specific
extracellular fiber composition.
tissue mechanics; hysteresivity
