호산구형 비용과 만성염증형 비용 조직에서 5-Lipoxygenase와 Cyclooxygenase-2의 발현：면역조직화학적 연구

Background and Objectives: Activation of the phospholipase A₂ in response to various stimuli, release ara- chidonic acid, which can be further metabolized by two major enzymatic pathways : cyclooxygenase (COX) and 5-lipoxygenase (5-LOX), leading to pro-inflammatory mediators, prostanoids and leukotrienes, respectively. Histologically, polyps are divided into four types. Among them, eosinophilic and chronic inflammatory polyps are common histologic types in nasal polyps. The aim of this study was to determine the expression of COX-2 and 5-LOX in eosinophilic polyps and chronic inflammatory polyps. Materials and Methods: 50 nasal polyps specimens were obtained during endoscopic sinus surgery and classified into eosinophilic and chronic inflammatory polyps. 11 normal nasal mucosa were taken from the inferior turbinate of patients who underwent septoplasty operation. The 5-LOX and COX-2 protein expression were determined by immunohistochemical staining. Results: The expression of 5-LOX and COX-2 protein were detected in nasal polyps and normal nasal mucosal tissues. 5-LOX was predominantly expressed in cytoplasm and nucleus of inflammatory cells and also found in submucosal glandular cells, smooth muscle cells of vascular walls, and surface epithelial cells. COX- 2 was strongly expressed in cytoplasm of inflammatory cells and also found in submucosal glandular cells, smooth muscle cells of vascular walls, and surface epithelial cells. The expression of COX-2 and 5-LOX were significantly increased in eosinophilic polyps compared with chronic inflammatory polyps and normal inferior turbinate. Conclusions: Both COX-2 and 5-LOX are important to develop nasal polyps. Difference between the two groups may reflect difference in disease severity or in the nature of the inflammatory process. (J Clinical Otolaryngol 2005;16:105–110)