ABSTRACT
Formaldehyde is a chemical, which is used traditionally for fixing the cadaver. It is vaporized during dissection and practical studying on cadaver. Studies show that this vapor can cause some clinical symptoms such as throat, eye, skin and nasal irritation. This study was designed to determine the histopathologic changes of rat tracheal mucosa while all of the experiments were exposed to formaldehyde for 18 weeks. This study was performed on 28, 6-7 weeks postnatal albino Wistar rats. The rats were divided into 3 case groups (E1: 4h/d, 4d/w; E2: 2h/d, 4d/w; E3: 2h/d, 2d/w) and 1 control group. The tracheal specimens were sectioned and stained with H&E technique for histopathologic study. An epithelial disorganization, cilia disappearance, slight dysplastic changes and slight subepithelial lymphocytic infiltration were observed in the case of E1. Epithelial disorganization, irregular cilia and slight subepithelial infiltration were seen in E2 and E3 groups. The results of this study show that "the more exposure to formaldehyde vapor, the more intense epithelial changes".
El formaldehido es un producto químico que se usa tradicionalmente para la fijación de cadáveres. Éste se vaporiza durante la disección y los estudios prácticos en el cadáver. Investigaciones han mostrado que este vapor puede causar algunos síntomas clínicos como la irritación de garganta, ojos, piel y mucosa nasal. Este estudio tuvo como objetivo determinar los cambios histopatológicos en la mucosa de la tráquea de la rata para lo cual todos los animales fueron expuestos al formaldehído, durante 18 semanas. El estudio fue realizado en 28 ratas albinas Wistar, con 6-7 semanas de vida. Las ratas fueron divididas en 3 grupos (E1: 4h/día, 4días/semana; E2: 2h/día, 4días/semana; E3: 2h/día, 2días/semana) y un grupo control. Fueron seccionadasas las tráqueas de los especímenes y teñidas con H&E para su estudio histopatológico. Una desorganización epitelial, desaparición de cilios, leves cambios dispásticos y leve infiltración linfocítica subepiteial fueron observados en el grupo E1. Desorganización epitelial, cilios irregulares y leve infiltración subepitelial fueron observados en los grupos E2 y E3. Los resultados de este estudio muestran que a mayor exposición al vapor del formaldehido, más intensos son los cambios epiteliales de la mucosa traqueal.
Subject(s)
Animals , Rats , Trachea/drug effects , Formaldehyde/toxicity , Trachea/pathology , Rats, Wistar , Disinfectants/toxicity , Mucous MembraneABSTRACT
This study was undertaken to investigate the histopathological change in the tracheal mucosa of rats by light microscope following acute exposure to ortho-chlorobenzylidene malononitrile(CS). 2.0g/m3 of CS was inhalated to experimental rats for 20 minutes per day during 3 days in a plastic chamber. The experimental animals were sacrificed at 12 hours, 24 hours, 3 days, and 5 days after CS gas exposure. Specimens were obtained from upper most part of tracheal mucosa of the rats. After H and E stain and PAS stain were performed, all specimens were observed by light microscope. The result were as follows: 1) At 12 hours after exposure , there were some cilia destruction, widening of lamina propria, and infiltration of inflammatory cells in subepithelial layer. Epithelial lining and goblet cells were well preserved. 2) At 24 hours after exposure, epithelial lining and basement membrane were destructed and goblet cells were decreased in number. Infiltration of inflammatory cells in subepithelial layer were as sustained and vascular congestion was observed. 3) At 3 days after exposure, regeneration of epithelial layer, goblet cells, and basement membrane were identified. In subepithelial layer, a few inflammatory cells were infiltrated. 4) At 5 days after exposure, intact epithelial layer and numerous normal goblet cells were appeared. Lamina propria was narrowed and no inflammatory cells were in subepithelial layer. The results suggested that the tracheal mucosa of the rats shows a siginificant degenerative change after acute exposure to ortho-chlorobenzylidene malononitirile. However, it was temporary and reversible change.