Post-exercise nasal vasoconstriction and hyporeactivity: possible involvement of neuropeptide Y.

Neuropeptide Y (NPY) is co-localized with noradrenaline (NA) in perivascular sympathetic nerve and is a vasoconstrictor. Pre-treatment with exogenous NPY markedly reduced nasal airway obstruction and rhinorrhea induced by the irritant capsaicin in control subjects. The aim of the present experiments was to study the time course variations of plasma concentrations of NA and NPY during and after intense exercise in 17 healthy volunteers. In parallel, changes in nasal airway resistance (NAR) were recorded. Nasal obstruction and rhinorrhea induced by capsaicin were compared after 30 min of rest and after 30 min of exercise. Both subjective and objective NAR were significantly reduced (p < 0.05) for over 15 min after the end of exercise. Plasma levels of NPY remained increased for more than 15 min after exercise whereas NA returned to basal values within less than 10 min. The increases of NAR and mucus production evoked by capsaicin were markedly attenuated for 30 min after exercise (p < 0.05). Variations of plasma NPY concentrations over time correlated better with post-exercise nasal vasoconstriction and hyporeactivity to capsaicin than NA. These observations suggest that endogenous NPY could be involved in the prolonged post-exercise nasal vasoconstriction and acts as a modulator of nasal airways reactivity.