Effects of short-term hydrocarbon inhalation on rat tracheal mucosa

Hydrocarbons used as solvents in industry are thought to have effects on respiratory system. However, its effect on tracheal morphology and function is poorly investigated. Therefore the present study attempted to investigate the rat tracheal structure following different types and concentrations of hydrocarbon exposure. To do this, 65 Swiss albino rats were divided into 6 groups. While control group animals were undergone no treatment, 5 experimental group animals received different types of hydrocarbons saturated in air, such as 1,2-dibromoethane, 1,1,1-trichloroethylene, naphthalene, carbontetrachloride and carbonsulphide at 1, 3 and 6 hour intervals in isolated chambers. Control group consisted of 5 rats whereas the experimental groups contained 60 rats (12 for each group). Tracheal tissue samples were collected from the control and experimental group animals, and were processed for light microscopy. Tracheal morphology underwent distinct alterations after 1, 3, and 6 hours of hydrocarbon exposure. Common tracheal features for all experimental groups were a thinner epithelial layer along with occasional exfoliation, hyparemic and dilated vasculature with intraluminal haemorage, and inflammatory cell infiltration into the underlying connective tissue. Tracheal glands taking place in the lamina propria seemed to be increased following several hydrocarbon exposure. In conclusion, it may be postulated that the hydrocarbons used in the present study cause irreversible tracheal alterations. Therefore one must take extreme caution when these toxic compounds are used.