Expression of cyclooxygenase in nasal polyps from atopic and nonatopic subjects

Cyclooxygenase (COX) I and 2 are two isoforms of a crucial enzyme in the me tabolism of arachidonic acid to prostaglandins, thromboxanes and prostacycl in. II is now clear that COX-1 is expressed in the majority of cells consti tutively, and COX-2 appears after stimulation. The role of cyclooxygenase e xpression in the pathophysiology of the airways has not been elucidated. in this study we aimed to compare cyclooxygenase expression in nasal polyps r emoved from well-defined atopic and nonatopic subjects. Monoclonal antibodi es against COX-total (detecting both COX-I and COX-2 epitopes) and anti-COX -2 combined with peroxidase-antiperoxidase (PAP) visualizing system were us ed to assess COX-total and COX-2 expression in cryostat sections of nasal p olyps from both groups of patients. Chromotrope R-2 or toluidine blue stain ing were used to detect the presence of eosinophils and mast cells, respect ively. We demonstrated that cryostat sections of nasal polyps from both gro ups of patients revealed COX-total and COX-2 expression with similar intens ity. There were no significant differences in distribution of COX-total or COX-2 immunoreactivity in nasal polyps tissue between atopic and nonatopic group. No correlation between density of cells expressing COX-2 and the num ber of mast cells and eosinophils was found. Our data indicate that COX-2 i s expressed in nasal polyps from both atopic and nonatopic patients.