Expression and localization of the thromboxane A2 receptor in human nasal mucosa.

Thromboxane A2 (TXA2) has been thought a potent mediator involved in allergic rhinitis, because TXA2 was recovered from the nasal lavage fluid of allergic rhinitis patients after allergen provocation and TXA2 receptor antagonists relief nasal allergic symptoms. In order to clarify the expression of TXA2 receptor in human nasal mucosa, we investigated TXA2 receptor mRNA expression and its protein localization by polymerase chain reaction (PCR) and immunohistochemistry, respectively. Human turbinates were obtained after turbinectomy from 10 patients with nasal obstruction refractory to medical therapy. RT-PCR analysis of total RNA from nasal mucosa demonstrated the expression of TXA2 receptor alpha mRNA. The immunohistochemical studies revealed that anti-TXA2 receptor alpha antibody labeled vascular smooth muscle cells, vascular endothelial cells, epithelial cells and submucosal glands in the nasal mucosa. The results may have an important clinical implication for understanding the role of TXA2 receptor on upper airway diseases such as allergic rhinitis and non-allergic rhinitis.