CYCLOOXYGENASE AND LIPOXYGENASE METABOLITE GENERATION IN NASAL POLYPS

A role of prostaglandins (PGs) and leukotrienes (LTs) in the pathogene sis of nasal polyps has been recently suggested. Cyclooxygenase (GO) p roducts (thromboxane B-2, PGE(2) and 6-keto PGF(1) alpha) and lipoxyge nase (LO) products (LTB4 and LTC4) were investigated by radioimmunoass ay in polyps, hypertrophic turbinates and nasal mucosa from 14 patient s with non-allergic (n = 6), allergic chronic rhinitis (n = 6) and asp irin-sensitive asthma (ASA) (n = 2), who underwent polypectomy. In all tissues CO metabolite levels were found higher than LO products (P < 0.01). Nasal polyps showed a significantly lower (P < 0.05) arachidoni c acid (AA) metabolism in comparison to nasal mucosa. In polyps of all ergic patients significantly higher LTB, levels (P < 0.001) and a tend ency to produce higher amounts of CO products in comparison to non-all ergic subjects were observed, whereas in turbinates of non-allergic pa tients LT levels were significantly higher in comparison to those of a llergic ones (P < 0.01). In ASA patients a decreased CO/LO ratio was f ound supporting the hypothesis of an imbalance of AA metabolism in thi s syndrome. These findings seem to indicate that the occurrence of nas al polyps may represent the result of different chronic inflammatory s timuli, regulated in part by AA metabolites.