Expression of 5-HT1B receptors in human nasal mucosa.

5-HT1B receptors were discovered in human nasal mucosa using immunocytochemistry. Strong immunoreaction was seen around small blood vessels mainly confined to the smooth muscle cell layer. In contrast, no immunoreaction for 5-HT1D was seen. The possibility of local release in connection with specific target receptors suggests a role for 5-HT in the regulation of vascular tone, glandular secretion and epithelial functions and that 5-HT1B receptor agonists may be of clinical importance.