Deakin University

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Overexpression of TGF-α increases lung tissue hysteresivity in transgenic mice

journal contribution
posted on 2001-01-01, 00:00 authored by J J Pillow, T R Korfhagen, M Ikegami, Peter Sly
Increased transforming growth factor (TGF)-α has been observed in neonatal chronic lung disease. Lungs of transgenic mice that overexpress TGF-α 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-α 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 (GL) and tissue elastance (HL) were obtained by fitting a model to each impedance spectrum. Hysteresivity (η) was calculated as GL/HL. There was a significant increase in η (P < 0.01) and a trend to a decrease in HL (P = 0.07) of TGF-α mice compared with the wild-type group. There was no significant change in Raw, I, or GL. Structural abnormality present in the lungs of adult TGF-α mice alters viscoelastic coupling of the tissues, as evidenced by a change in η.



Journal of Applied Physiology






2730 - 2734