Alveolar epithelial fluid clearance mechanisms are intact after moderate hyperoxic lung injury in rats
Autor: | Deng Feng Luo, Chrystelle Garat, Michael A. Matthay, Michel Meignan, Christian Jayr |
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Rok vydání: | 1997 |
Předmět: |
Pulmonary and Respiratory Medicine
Lung Diseases Male Pathology medicine.medical_specialty medicine.drug_class Blood Pressure Pulmonary Edema Lung injury Hyperoxia Critical Care and Intensive Care Medicine Epithelium Iodine Radioisotopes Bronchodilator Albumins Terbutaline Ventilation-Perfusion Ratio Medicine Animals Rats Wistar Lung Respiratory Distress Syndrome Blood-Air Barrier business.industry Respiratory disease Organ Size respiratory system Adrenergic beta-Agonists Pulmonary edema medicine.disease Epithelial fluid transport respiratory tract diseases Rats Oxygen Pulmonary Alveoli Disease Models Animal medicine.anatomical_structure Extravascular Lung Water medicine.symptom Pulmonary alveolus Radiopharmaceuticals Cardiology and Cardiovascular Medicine business |
Zdroj: | Chest. 111(5) |
ISSN: | 0012-3692 |
Popis: | The capacity of the alveolar epithelial barrier to remove excess alveolar fluid from the airspaces of the lung was studied in an experimental model of moderate hyperoxic lung injury. Rats were exposed to 100% oxygen for 40 h in an exposure chamber and compared with control animals exposed to room air. Extravascular lung water was calculated gravimetrically. Alveolar and lung liquid clearance were studied over 1 h by instillation of a 5% albumin solution with 1.5 microCi of 125I-labeled albumin (6 mL/kg into both lungs). The concentration of both the unlabeled and labeled albumin was used to calculate alveolar liquid clearance. Hyperoxic rats developed pulmonary edema, with a 33% increase in extravascular lung water to 5.3 +/- 0.1 g of water per gram of dry lung, compared with 4.0 +/- 0.2 g of water per gram of dry lung in control rats (p0.05). This degree of edema was associated with a significant increase in the alveolar-arterial oxygen difference (241 +/- 61 vs 124 +/- 14 mm Hg in control animals exposed to room air, p0.05). Despite this moderate degree of lung injury, alveolar fluid clearance was normal (30 +/- 3%) compared with control rats (33 +/- 6%). Furthermore, the hyperoxic injured rats responded normally to an exogenous beta-adrenergic agonist (terbutaline, 10(-4) mol/L) with a 67% increase in the rate of alveolar liquid clearance (50 +/- 5%). Thus, in the setting of moderate hyperoxic lung injury, the alveolar epithelial barrier is still capable of removing fluid at a normal rate and responding to beta-adrenergic agonist treatment. These experimental results have potential clinical implications for patients with acute lung injury. |
Databáze: | OpenAIRE |
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