ABSTRACT
The objective of this study was to determine the duration of the pulmonary response in guinea pigs to a single six hour cotton dust exposure. A total of twenty five guinea pigs were exposed to either an atmosphere of 10 mg/m3 cotton dust (approximate mean, measured continuously) or clean air. The standard dust DB (5/89) was generated in a modified Pitt-3 acoustic dust generator. The breathing frequency of the animals was measured before the exposure, immediately post-exposure, and each day until sacrifice. Five animals were sacrificed at 1, 2, 3 and 4 days post-exposure along with five control animals that had been maintained in clean air. Upon sacrifice, pulmonary lavage was performed on the animals, with the supernatant of the first lavage frozen for detection of tumour necrosis factor, lactate dehydogenase, superoxide dismutase and N-acetyl b-d-glucosaminidase activities. Differential cell counts were determined on the cells harvested from the lavage. Chemiluminescence was measured to determine the degree of macrophage activation.
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