Topographical distribution of trigeminal receptor expression in the nasal cavity

BACKGROUND: Topographical differences in trigeminal receptor distribution of the nasal cavity has been investigated so far indirectly using various agonists to stimulate receptors in different locations. However, polymodal activation of trigeminal receptors poses difficulties in such investigation. The aim of our study was to examine the distribution of trigeminal receptor mRNA expression using quantitative PCR. METHODOLOGY: A prospective study was performed in 18 healthy volunteers. Mucosal biopsies were obtained from five different endonasal locations (covering the anterior, posterior and lateral nasal cavity) for receptor mRNA quantification by means of RTPCR. RESULTS: The highest overall level of RNA expression was found for TRPV1, followed by ACCN3, TRPA1 and TRPM8. Identical distribution pattern could be shown for each investigated area of the nasal cavity. Highest overall receptor density was found in the posterior septum due to high TRPV1 and ACCN3 receptor expression. CONCLUSIONS: For the first time, we demonstrate a distinct trigeminal receptor RNA distribution pattern of the nasal mucosa. The highest overall distribution level was found in the posterior nose.