Biochemical and cellular changes in bronchoalveolar lavaged samples from rats after inhalation of mosquito-coil smoke

A group of 30 female albino rats were exposed to mosquito-coil smoke, 8 hours a day, 6 days per week, for 6 months. Another group which was exposed to air served as control. At the end of the experiment, the enzyme activities, total protein and lecithin contents as well as cellular responses in the lung lavage between the control and smoke-exposed rats were compared. Morphological observations using scanning and transmission electron microscopy demonstrated that the alveolar macrophages of smoke-exposed rats lost their typical ruffled membranes. They possessed small cytoplasmic processes on their smooth cell surfaces, small particles in phagolysosomes and mitochondria with a very electron-dense matrix. The levels of total protein and lecithin and the activities of lactate dehydrogenase, acid phosphatase and beta-glucuronidase in the lung-lavage fluid of smoke-exposed rats were significantly (P less than 0.05) higher than those of the controls. Increases (P less than 0.05) of serum enzymes, including lactate dehydrogenase, aspartate aminotransferase, isocitrate dehydrogenase and aldolase, indicated damage of liver tissues, but the levels of serum urea and urea nitrogen remained at the control levels implying normal functions of the kidneys of the mosquito-coil smoke-exposed rats. The level of serum tri-iodothyronine also increased significantly (P less than 0.05), but thyroxine remained at the control level.