5-HT7 receptorsare over-expressed in patients with nasal polyps.

Nasal polyposis (NP) is an inflammatory disease of the paranasal sinuses and nasal cavity. The primary purpose of our study is to determine the expression of 5-HT receptors both in nasal polyps and in healthy tissue in the nasal cavity. The subsequent aim is to compare the expression of 5-HT receptors in patients with NP and in inferior turbinate tissue (control).The study included 60 participants (40 with NP and 20 controls) aged 35 to 62 years. Nasal polyp samples were collected from all patients and relative expression analyses were performed. RT-PCR analysis of nasal polyps and control tissue identified 5-HT receptor expression in the nasal cavities of controls. This expression was approximately 67 times higher in nasal polyp tissue than in healthy tissue. Our study identifies the expression of 5-HT receptors in the nasal cavity for the first time. It is also the first demonstration of increased 5-HT receptor expression in tissue from nasal polyps, which occur in the paranasal sinuses and nasal cavity.