ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of CLCA3 and Muc5ac in nasal mucosa in allergic rhinitis rats and the effects of glucocorticoid on its expression.</p><p><b>METHODS</b>Thirty SD rats were randomly divided into allergic rhinitis group, dexamethasone group and control group. Expression of CLCA3 mRNA and Muc5ac protein in nasal mucosa were detected by RT-PCR and immunohistochemical assay, respectively.</p><p><b>RESULTS</b>CLCA3 mRNA and Muc5ac protein in allergic rhinitis group were significantly higher than those in control group (t = 8.565, 5.317, P < 0.01, respectively). The increased expression of CLCA3 mRNA in allergic rhinitis group was well correlated with the expression of Muc5ac protein and the correlation coefficient was 0.813 (P < 0.05). After treatment with dexamethasone, the expression of CLCA3 mRNA and Muc5ac protein was notably lower than that in allergic rhinitis group (t = 3.102, 2.226, P < 0.05, respectively).</p><p><b>CONCLUSIONS</b>The stronger gene expression of CLCA3 exists, complicated with mucus overproduction in the nasal mucosa of allergic rhinitis rats. CLCA3 expression may play a pivotal role in mucus overproduction in allergic rhinitis. Dexamethasone substantially downregulates the expression of CLCA3 mRNA and Muc5ac protein.</p>