Effects of Hyperbaric Oxygen Therapy on Rat Nasal Mucosa

The objective of this study was to evaluate the histopathologic effects of hyperbaric oxygen (HBO) therapy on the rat nasal mucosa. Twelve adult Sprague-Dawley rats, each weighing 180-220 g, were used as experimental animals. The rats were divided into HBO (hyperbaric oxygen) and control group. The rats in the HBO group (n = 6) were placed into a 20-liter HBO chamber (2.5 atmospheres absolute [ATA], 25-26°C with 100 % oxygen) for 90 min per day. The rats received hyperbaric oxygen over a period of 7 days. The rats in the control group (n = 6) were not given HBO. All animals were sacrificed at the end of the study, and nasal tissue samples were prepared. The sections were stained with Haematoxylin and Eosin (H-E), Periodic acid-Schiff (PAS) and Trichrome-Masson to observe the under a light microscope. Immunoreactivity of pseudostratified epithelial cells of the nasal mucosa was assessed with E-cadherin expression by immunohistochemical staining. There were significant differences in the average histopathological score between the groups exposed and non-exposed to HBO. In the HBO group, degenerative changes in epithelial cells were observed. The goblet cells showed expansion of their structure. Mononuclear lymphocyte infiltration, dilation of blood vessels, and hemorrhage were observed in considerable areas of connective tissue. In the immunohistochemical evaluation of E-cadherin expression, there were no significant differences between the two groups.