Effect of cooling on electrical field stimulation and norepinephrine-induced contraction in isolated hypertrophic human nasal mucosa

Background: Exposure to cold causes cutaneous vasoconstriction to reduce body heat loss, while the nasal cavity warms up the inspired cold air. This suggests cooling might evoke a different response in nasal mucosa blood vessels than in cutaneous blood vessels. Thus, the aim of this study was to evaluate the effect of cooling (to 24°C) on the vascular response of isolated nasal mucosa. Methods: An in vitro isometric contraction of nasal mucosa excised from patients suffered from chronic nasal congestion was continuously recorded. Either electrical field stimulation (EFS) or exogenous norepinephrine (NE) was applied to the turbinate mucosa strip at 37 and 24°C, and the influence of cooling (to 24°C) was evaluated. Results: EFS (1, 2, 4, and 8 Hz) produced frequency-dependent contractions at 37 and 24°C. Cooling did not alter the magnitude but significantly prolonged the duration of EFS-induced contraction. Exogenous NE (10^-8 to 10^-4 M) produced concentration-dependent contractions at 37 and 24°C. Cooling significantly enhanced the contractile responses evoked by NE between 3 × 10^-6 and 1 × 10^-4 M. Conclusion: Cooling (to 24°C) prolonged the EFS-induced and enhanced NE (3 × 10^-6 to 1 × 10^-4 M)-induced contraction of isolated human nasal mucosa.