Using the pleurai window approach, we measured the hydraulic pressure by micropuncture technique in the perivascular pulmonary interstitium (Pip) in anesthetized rabbits exposed up to 6h of hypoxia induced by 12% O2 breathing. Through image analysis we also estimated the morphological changes of precapillary microvessels and perivascular interstitium. Pulmonary artery pressure was 16 ± 8 cmH2O in control and increased to 30 ± 8 cmH2O after 6h of hypoxia. Pip was -10 ± 2 cmH2O in control and increased to 0 ± 2.3 cmH2O in hypoxia. After 100 min of hypoxia the diameter of arterioles averaging -13.5±9 μn (range 50-35 μm) decreased significantly by 7.2±1.2 μm and remained thereafter steady. The thickness of the perivascular interstitium averaged 29±8 μm in control and increased significantly by 5 ±1 μm at 60 min. Plasma protein concentration was 5.1 ± 0.4 g/dl in control and decreased at a rate of 0.16 g/(dlh) during hypoxia. Interstitial protein concentration derived from samples of interstitial fluid obtained from wicks implanted in the intercostal muscles was 2.5±0.4 g/dl in control and 2.8±0.4 g/dl after 6h of hypoxia. The data indicate that hypoxia exposure increases filtration rate and protein escape from microcirculation into lung interstitium. Precapillary vasoconstriction occurred similarly to what previously observed in conditions of pulmonary interstitial edema.
|Publication status||Published - 1997|
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology