To evaluate the importance of
histamine and
peptide leukotrienes (LTs) in the development of nasal mucosal swelling in nasal
allergy,
H1 receptor antagonist (
mequitazine, 6 mg, in 2 divided doses, Rhône-Poulenc Rorer, France) and LT receptor antagonist (
ONO-1078,
pranlukast, 450 mg, in 2 divided doses, Ono
Pharmaceutical Co, Ltd, Osaka) were administered orally for 7 days to 16 subjects with perennial nasal
allergy to house dust mites, and the effects of receptor blockers of these chemical mediators on the effective cross-sectional area of the nasal cavity (ECA) at rest, at exercise load, at
antigen challenge, and at exercise load following
antigen challenge were studied. After the administration of
H1 receptor antagonist, ECAs at all measurement points slightly increased, but no statistical significance was observed. On the other hand, LT receptor antagonist inhibited ECAs 10 minutes after exercise load, just after the end of
antigen challenge, 10 minutes later, and at exercise load following
antigen challenge with statistical significance. These results suggest that LTs are involved markedly, and
histamine slightly, in the development of nasal mucosal swelling in nasal
allergy.