ABSTRACT
Background: Ozone exposure could increase lung damage induced by airborne particulate matter. Particulate matter lung toxicity has been attributed to its metallic content. Aim: To evaluate the acute effect of intratracheal administration of copper sulfate (CuSO4) on rat lungs previously damaged by a chronic intermittent ozone exposure. Material and Methods: Two-months-old male Sprague-Dawley rats were exposed to 0.5 ppm ozone four h per day, five days a week, during two months. CuSO4 was intratracheally instilled 20 h after ozone exposure. Controls breathed filtered air or were instilled with 0.9% NaCl or with CuSO4 or were only exposed to ozone. We evaluated lung histopathology. F2 isoprostanes were determined in plasma. Cell count, total proteins, γ glutamyl-transpeptidase (GGT) and alkaline phosphatases (AP) were determined in bronchoalveolar lavage fluid (BALF). Results: Ozone increased total cell count, macrophages, proteins and AP in BALF (p < 0.05), and induced pulmonary neutrophil inflammation. CuSO4 plus air increased plasma F2 isoprostane levels and total cell count, neutrophils and proteins in BALF (p < 0.05). Histopathology showed foamy macrophages. Ozone plus CuSO4 exposed animals showed a neutrophil inflammatory lung response and an increase in total cell count, proteins, GGT and AP in BALF (p < 0.05). Foamy and pigmented alveolar macrophages were detected in all lungs of these animals (p < 0.001). Conclusions: Intratracheal instillation of a single dose of CuSO4 in rats previously subjected to a chronic and intermittent exposure to ozone induces a neutrophil pulmonary inflammatory response and cytoplasmic damage in macrophages.