Histopathological changes of rat larynx mucosa with exposure to chronic thinner inhalation

Histopathological changes in nasal mucosa, trachea, and pulmonary system with exposure to chronic thinner inhalation have been studied in the literature. However, the possible changes in larynx mucosa, which is a part of the upper airway tract, have not been studied yet. The aim of this study is to determine the histopathological changes of rat larynx mucosa with exposure to chronic thinner inhalation.

Randomized trial. The study was conducted at the animal care facility of Haydarpasa Numune Education and Research Hospital.

Fifty-one Sprague-Dawley rats were used throughout the experiment. Four groups of rats inhaled thinner in a glass cage for 2, 4, 8, and 12 weeks respectively. Seven rats inhaled only the air in the room as the control group.

The comparison of inflammation and exocytosis in the control and 2 week groups revealed no significant difference (P>0.05), but from the beginning of 4 weeks of thinner inhalation, statistically significant differences were observed (P<0.05). From the beginning of 8 weeks of thinner inhalation, statistically significant differences were observed in larynx mucosa when we assessed metaplasia and cilia loss distribution among groups (P<0.05).

On the basis of histopathological evaluations, it was shown that the harmful effect of inhalation of thinner in high concentrations to larynx mucosa is similar to the effect on other organs of the respiratory system.