RT Journal Article
SR Electronic
T1 Interstitial pressure and lung oedema in chronic hypoxia
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP erj00667-2010
DO 10.1183/09031936.00066710
A1 I. Rivolta
A1 V. Lucchini
A1 M. Rocchetti
A1 F. Kolar
A1 F. Palazzo
A1 A. Zaza
A1 G. Miserocchi
YR 2010
UL http://erj.ersjournals.com/content/early/2010/08/06/09031936.00066710.abstract
AB We evaluated how the increase in lung interstitial pressure correlates with the pulmonary vascular response to chronic hypoxia.In control and hypoxic (30days, 10%O2) Wistar male rats, we measured: pulmonary interstitial pressure, cardiac and hemodynamic parameters by echocardiography, and performed lung morphometry on tissue specimens fixed in situ.In control animals, pulmonary interstitial pressure, air/tissue volume ratio and capillary vascularity index in the air-blood barrier were respectively: −12±2.03cmH2O, 3.9 and 0.43. After hypoxia exposure, the corresponding values of these indexes in apparently normal lung regions, were: 2.6±1.7cmH2O, 3.6, and 0.5. In oedematous regions the corresponding values were: 12±4cmH2O, 0.4 and 0.3. Furthermore, in normal regions the density of precapillary vessels (diameter range ∼50–200 μm) increased and their thickness/internal diameter ratio decreased, while opposite results were found in oedematous regions. Pulmonary artery pressure increased in chronic hypoxia relative to control (39.8±5.9 vs 26.2±2.2 mmHg).Heterogeneity in local lung vascular response contributes to developing pulmonary hypertension in chronic hypoxia. In oedematous regions the decrease in capillary vascularity correlated to the remarkable increase in interstitial pressure and morphometry of the precapillary vessels suggested an increase in vascular resistance; the opposite was true in apparently normal regions.