TY - JOUR
T1 - Overexpression of TGF-alpha increases lung tissue hysteresivity in transgenic mice
AU - Pillow, J.J.
AU - Pillow, Jane
AU - Korfhagen, T.R.
AU - Ikegami, M.
AU - Sly, P.D.
PY - 2001
Y1 - 2001
N2 - Increased transforming growth factor (TGF)-alpha has been observed in neonatal chronic lung disease. Lungs of transgenic mice that overexpress TGF-alpha develop enlarged air spaces and pulmonary fibrosis compared with wild-type mice. We hypothesized that these pathological changes may alter the mechanical coupling of viscous and elastic forces within lung parenchyma. Respiratory impedance was measured in open-chested, tracheostomized adult wild-type and TGF-alpha mice by using the forced oscillation technique (0.25-19.63 Hz) delivered by flexiVent (Scireq, Montreal, PQ). Estimates of airway resistance (Raw), inertance (I), and the coefficients of tissue damping (G(L)) and tissue elastance (H-L) were obtained by fitting a model to each impedance spectrum. Hysteresivity (eta) was calculated as G(L)/H-L. There was a significant increase in eta (P <0.01) and a trend to a decrease in H-L (P = 0.07) of TGF- mice compared with the wild-type group. There was no significant change in Raw, I, or G(L). Structural abnormality present in the lungs of adult TGF-alpha mice alters viscoelastic coupling of the tissues, as evidenced by a change in eta.
AB - Increased transforming growth factor (TGF)-alpha has been observed in neonatal chronic lung disease. Lungs of transgenic mice that overexpress TGF-alpha develop enlarged air spaces and pulmonary fibrosis compared with wild-type mice. We hypothesized that these pathological changes may alter the mechanical coupling of viscous and elastic forces within lung parenchyma. Respiratory impedance was measured in open-chested, tracheostomized adult wild-type and TGF-alpha mice by using the forced oscillation technique (0.25-19.63 Hz) delivered by flexiVent (Scireq, Montreal, PQ). Estimates of airway resistance (Raw), inertance (I), and the coefficients of tissue damping (G(L)) and tissue elastance (H-L) were obtained by fitting a model to each impedance spectrum. Hysteresivity (eta) was calculated as G(L)/H-L. There was a significant increase in eta (P <0.01) and a trend to a decrease in H-L (P = 0.07) of TGF- mice compared with the wild-type group. There was no significant change in Raw, I, or G(L). Structural abnormality present in the lungs of adult TGF-alpha mice alters viscoelastic coupling of the tissues, as evidenced by a change in eta.
M3 - Article
VL - 91
SP - 2730
EP - 2734
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 1522-1601
ER -