Abstract
Chemical burn of upper respiratory tract caused by hydrochloric acid vapors was used as a model of tracheal epithelium damage. To evaluate the possibility of neutralization of the oxidative stress, we applied exogenous antioxidant enzymes directly into the rat trachea upon burn. Since superoxide radicals and inorganic and organic hydroperoxides are the major ROS types, in our experiments we used Mn-superoxide dismutase (Mn-SOD), peroxiredoxin 6 (Prx6), chimeric enzyme PSH, combining superoxide dismutase and peroxidase activities.
The application of 1 mg/ml of Mn-SOD in a burnt trachea following 30 min after the burn injury resulted in a fast and complete destruction of tracheal epithelium associated with heavy bleeding from the rat larynx and subsequent death of the animal. When using reduced Mn-SOD concentration (0.1 mg/ml) the animals did not die, but their tracheal epithelium was significantly damaged. Completely different results were obtained upon the application of Prx6 and the chimeric PSH into the burnt trachea. The morphological analysis of the tracheal epithelium structure following one day after the burn and the application of both proteins demonstrated considerable preservation of the tracheal epithelium with a significant survival rate of ciliated cells, which were not present in the controls. Morphological analysis of the tracheal epithelium conducted in three days after the injury testified a similar pattern with even more pronounced preservation of the epithelium, witnessing intensive regenerative processes in the trachea upon the application of these proteins.
- © 2014 ERS