Temperature conditioning of nasal air: effects of vasoactive agents and involvement of nitric oxide

Nitric oxide(NO) is released into nasal air,but its function is unknown. We hypothesized that nasal vascular tone and/or flow influences temperature c onditioning of nasal air and that NO participates in this process. We measu red nasal air temperature (via a thermocouple) and exhaled nasal NO release (by chemiluminescence) in five humans and examined the effects of an aeros olized vasoconstrictor (oxymetazoline), a vasodilator(papaverine), N-G-nitr o-L-arginine methyl ester, an inhibitor of NO synthase, or saline (control) . Compared with saline (which caused no changes in nasal air temperature or exhaled NO release), oxymetazoline (0.05%) reduced nasal air temperature a nd NO release (130.8 +/- 15.1 to 81.3 +/- 12.8 nl.min(-1).m(-2); P < 0.01). Papaverine (0.01 M) increased nasal air temperature and NO release (131.8 +/- 13.1 to 157.2 +/- 17.4 nl.min(-1).m(-2); P < 0.03). N-G-nitro-L-arginin e methyl ester reduced nasal air temperature and NO release (123.7 +/- 14.2 to 44.2 +/- 23.7 nl.min(-1).m(-2); P < 0.01). The results suggest that vas cular tone and/or flow modulates temperature conditioning and that NO may p articipate in that function.