Effects of emissions from sugar cane burning on the trachea and lungs of Wistar rats.

To evaluate the effects of exposure to emissions from sugar cane burning on inflammatory mechanisms in tissues of the trachea and lung parenchyma in Wistar rats after different periods of exposure.This was an experimental open randomized study. The animals were divided into four groups: a control group (CG) underwent standard laboratory conditions, and three experimental groups were exposed to emissions from sugar cane burning over different periods of time, in days-1 (EG1), 7 (EG7), and 21 (EG21). After euthanasia with 200 mg/kg of ketamine/xylazine, fragments of trachea and lung were collected and fixed in 10% formalin. Histological analyses were performed with H&E and picrosirius red staining.No inflammatory infiltrates were found in the tissues of CG rats. The histological examination of tissues of the trachea and lung parenchyma revealed that the inflammatory process was significantly more intense in EG7 than in the CG (p < 0.05 and p < 0.01, respectively). In comparison with the CG and EG1, angiogenesis in the lung parenchyma and collagen deposition in tracheal tissues were significantly greater only in EG21 (p < 0.001 and p < 0.01, respectively).In this sample, emissions from sugar cane burning induced acute focal and diffuse inflammation in the lamina propria of tracheal tissues, with no loss of ciliated epithelial tissue. In the lung parenchyma of the animals in the experimental groups, there was interstitial and alveolar edema, together with polymorphonuclear cell infiltrates.Avaliar os efeitos da exposicao a fumaca da queima da cana-de-acucar sobre mecanismos inflamatorios em tecidos de traqueia e de parenquima pulmonar de ratos Wistar apos diferentes periodos de exposicao.Estudo experimental, randomizado, nao cego. Os animais foram divididos em quatro grupos: controle (GC), sob condicoes padrao de laboratorio e os demais expostos a fumaca da queima da cana-de-acucar por diferentes periodos: em 1 (GE1), 7 (GE7) e 21 (GE21) dias. Apos a eutanasia com 200 mg/kg de ketamina/xilazina, foram coletados fragmentos de traqueia e pulmao e fixadas em formol 10%. Analises histologicas foram realizadas com coloracao com H&E e picrosirius.Nao houve infiltrado inflamatorio nos tecidos no GC. O processo inflamatorio na analise histologica de tecidos de traqueia e de parenquima pulmonar foi significativamente mais intenso no GE7 quando comparado ao GC (p < 0,05 e p < 0,01, respectivamente). Em comparacao com os grupos GC e GE1, apenas no GE21 foi observada angiogenese significativa no parenquima pulmonar e aumento significativo de depositos de colageno em tecido de traqueia (p < 0,001 e p < 0,01, respectivamente).Nesta amostra, a fumaca da queima de cana-de-acucar induziu processo inflamatorio focal, difuso e agudo em tecidos de traqueia na lâmina propria, sem perda do tecido epitelial ciliado. Houve presenca de edemas intersticiais e alveolares e infiltrados de celulas polimorfonucleares no parenquima pulmonar nos animais dos grupos experimentais.