Electrical Impedance and Expression of Tight Junction Components of the Nasal Turbinate and Polyp

Purpose: We investigated the electrical impedance and expression of tight junction components of the turbinate mucosa, nasal polyp, and normal skin. Procedures: The inferior turbinate and nasal polyp of patients with chronic rhinosinusitis and the postauricular skin of patients with otitis media were examined. Electrical impedance was measured in vivo using a tissue conductance meter. Expressions of claudin-1 and tricellulin were examined by fluorescence immunohistochemistry and quantitative RT-PCR. Results: Electrical impedance was higher in the skin than in the turbinate and polyp, but did not differ between the turbinate and polyp. Immunoreactivities for claudin-1 and tricellulin were seen in the epithelial/epidermal layer. Expression of claudin-1 was higher in the skin than in the turbinate and polyp. The polyp tended to show higher expression of claudin-1 but showed lower expression of tricellulin than the turbinate. The ratio of claudin-1 to tricellulin was highest in the skin and lowest in the turbinate. The correlation between expressions of the two tight junction components was strongly positive in the skin (r = 0.964) and negative (r = -0.527) in the turbinate and polyp. Conclusions: These results suggest that the roles of claudin-1 and tricellulin in barrier function may be complementary, and may thereby maintain a constant level of permeability of the mucosal tissues.