LIGHT AND SCANNING ELECTRON MICROSCOPIC STUDY OF THEEFFECT OF GASOLINE INHALATION ON RAT TRACHEA.PROTECTIVE ROLE OF VITAMIN C
Dalia M. Elmarakby; Nagla M. Salama
Department of Histology, Faculty of Medicine, Cairo University
Background and Aim of work: the number of people exposed to gasoline has been greatly increased over the past few years. The present study was conducted to investigate the effect, and the underlying mechanism, of intermittent gasoline vapor inhalation on the histological structure of rat trachea as well as to evaluate the possible protective role of vitamin C. Materials and Methods: this study included 18 adult male albino rats equally classified into 3 groups: control group, group exposed to gasoline vapor (6 h daily, 5 days a week for 4 weeks) and group exposed to gasoline vapor (as the previous group) and supplemented by vitamin C 200 mg/kg/day during the period of exposure. Tracheal specimens from all rats were prepared and subjected to scanning electron microscopic and light microscopic studies, using H&E and PAS stains as well as immunohistochemical stain for p53. The number of goblet cells/ low power field and the area% & optical density of p53 immunostaining were detected. All measurements were statistically analyzed.Results: the tracheas of rats exposed to gasoline showed many epithelial alterations, in the form of occasional clumping &loss of cilia, frequent destruction and desquamation of epithelial cells and goblet cell collapse. The lamina propria of mucosa and submucosa showed many congested blood vessels and heavy inflammatory cell infiltration. Intense p53 immunostaining was also detected in the apices of epithelial cells, C.T cells and tracheal glands. Meanwhile, the tracheas of rats supplemented with vitamin C showed less histological alterations and significant decrease in p53 area % and optical density as compared with the non-supplemented group. Conclusion: intermittent exposure to gasoline vapor could greatly disturb the mucociliary tracheal barrier and induce excessive damage of tracheal epithelial cells through p53 activation. Vitamin C supplementation has partial protective effect.