Final Report. Development Of Lung Surfactant Toxicological Tests.
Studies on the properties of small airways and alveoli for following respiratory disease in animals and tests for detection of lung disease in humans were conducted. Different types of experiments were conducted using trapped gases in isolated rat lungs. The stability of the small airways and alveoli was determined by placing an isolated rat lung into a plethysmograph which was placed into a larger chamber in which ambient pressure could be changed. Degassing was accomplished by oxygen absorption atelectasis using normal blood perfusion, followed by vacuum degassing after removal of the lung from the animal. A model was developed for gas trapping that included menisci formation within small airways, taking into account ratios of length to diameter as a function of lung inflation. In the plethysmograph, some gas was not in communication with the trachea and was trapped at maximum lung volume, mainly behind menisci or in foam or bubbles. The amount of gas trapped differed with different gases. The trapped gas was directly related to the solubility and molecular weight of the gas. The amount of fluid present was an important factor.
NIOSH-Author; Biochemical-analysis; Pulmonary-function-tests; Lung-disorders; Respiratory-system-disorders; Animal-studies; Fumes; Air-contamination;
NTIS Accession No.
NIOSH, U.S. Department of Health and Human Services, 10 pages