REDUCTION BY N-G-NITRO-L-ARGININE METHYL ESTER (L-NAME) OF ANTIGEN-INDUCED NASAL AIRWAY PLASMA EXTRAVASATION IN HUMAN-SUBJECTS IN-VIVO

In non-allergic subjects, histamine induced a reduction of minimal nas al cross-sectional area (Amin) and an increase in albumin release into nasal lavage. The effect of histamine on albumin release was inhibite d by pretreatment with N-G-nitro-L-arginine methyl ester (L-NAME), 1 m u mol but not by D-NAME, 1 mu mol. L-NAME, 1 and 10 mu mol, did not in hibit the histamine-induced reduction of Amin. In subjects allergic to grass pollen, antigen challenge induced a reduction in Amin that was not changed by pretreatment with L-NAME, and an increase in albumin re lease that was inhibited by L-NAME, 1 mu mol. The data support a role for nitric oxide in mediating plasma extravasation in the nose induced by antigen challenge or histamine.