Pathogenesis of rhinitis in rats with experimentally induced hypothyroidism

Hypothyroidism is accepted as one of the hormonal factors leading to non-allergic rhinitis. Nasal obstruction and runny nose due to an increase in submucosal connective tissue and mucous gland hypertrophy are the prominent symptoms in hypothyroidism-induced rhinitis at humans. The aim of this study was to analyze the biochemical and histopathological changes in the nasal mucosa of the rats with thyroidectomy-induced hypothyroidism and to compare them with those of a control group.

A total of 60 adult male Wistar Albino rats were included in the study. The rats constituting the test and the control groups were randomly divided into 3 subgroups (T1-3 and C 1-3). While the rats in the test group underwent thyroidectomy, in the control group the incision was sutured without any interventions after exposure of thyroid tissues of the rats. The nasal and paranasal sinus regions of all the rats were carefully dissected and tissue samples were obtained for pathological examinations.

In the rats in T1, T2, and T3, the decrease in serum glucuronic acid levels before and after thyroidectomy was statistically significant (p = 0.001, p = 0.003, and p = 0.002, respectively). The difference between the test and the control groups was statistically significant in terms of inflammation at the end of 12 weeks (p = 0.002).

An increase in acid mucopolysaccharidase production due to TSH has been suggested to cause congestion in tissues. Although our study supports the data in the literature up to date, we consider that further clinical and experimental studies are necessary for this verification.