EFFECT OF BRONCHOPULMONARY LAVAGE ON LUNG RETENTION AND CLEARANCE OF PARTICULATE MATERIAL IN HAMSTERS

Hamsters were exposed to an aerosol of fused aluminosilicate particles (FAP) labeled with Co-57. Three groups of animals were given bronchopulmonary lavage, beginning at either 1 week, 1 month, or 6 months after exposure. Each treated group was lavaged eight times over a period of 25 days. Each lavage involved 10 saline washes of the lungs. For each group, about 60-70% of the body content of Co-57 at the start of lavage treatment was removed; nearly half of this was recovered in the first two lavages. A positive correlation was demonstrated between the macrophage content and Co-57 activity of the washings. The subsequent fractional clearance rate of Co-57 from lavaged animals was not significantly different from that in a group of untreated control animals.