| pubmed-article:12205569 | pubmed:abstractText | We examined the effect of accelerated lung growth, induced by in utero tracheal occlusion (TO), on lung liquid uptake in near-term fetal sheep. In utero TO was performed in five fetal sheep at 110 days of gestation (term, approximately 145 days); six SHAM operated fetuses served as controls. The rate of liquid movement across the pulmonary epithelium was measured, using a previously established technique, in anesthetized fetal sheep between 133-137 days of gestation during a 2-hr adrenaline infusion (0.50 microg/min/kg, I.V.) and while lung luminal pressure was maintained at 5 mmHg. The rate of fetal lung liquid uptake was linear in all fetuses (mean r(2) < 0.97, n = 11). Mean values of lung liquid uptake expressed in relation to dry lung weight and luminal surface area of the right lung were significantly lower in TO fetuses (1.8 +/- 0.3 mL/hr/g and 1.0 +/- 0.2 mL/hr/m(2)) than in SHAM fetuses (2.6 +/- 0.2 mL/hr/g and 1.8 +/- 0.1 mL/hr/m(2)); surface area of the right lung was 140% greater in TO fetuses than in SHAM fetuses. There was a linear relationship between lung liquid uptake and pulmonary epithelial surface area in SHAM animals, but not in TO fetuses. We hypothesize that loss of alveolar epithelial type-II cells induced by increased levels of fetal lung expansion may impair alveolar liquid clearance in the perinatal period. | lld:pubmed |
