간접흡연에 의한 소기도 및 폐실질의 초기 변화에 관한 초미세형태학적 검색

Abstract

Cigarette smoking induces small airway diseases and deterioration in the lung function, and progresses to pulmonary parenchymal alteration. Early respiratory bronchiolitis and pulmonary parenchymal alteration were produced in Sprague-Dawley rats by daily exposure of sidestream cigarette smoke for one month, using a smoking chamber designed by authors. Experimental group A (n=5) was sacrificed after smoke of one cigarette/day, group B (n=5) with three cigarettes/day, and group C (n=7) with five cigarettes/day for one month. The early changes of small airway and pulmonary parenchyma were examined by light microscope, transmission and scanning electron microscopes. Under light microscope, there were multifocally alveolar collapses, dilatation of respiratory bronchioles, alveolar ducts and alveolar spaces, and increase in number of brown-pigmented alveolar macrophages in alveoli around the respiratory bronchioles. Under transmission electron microscope, irregularly shaped Clara cells with decreased number of secretory granules, collapse of alveolar walls, and mild injury of type Ⅰ and Ⅱ epithelial cells were seen. Under scanning electron microscope, scattered foci of alveolar collapse, irregular dilatation of alveolar ducts, alveolar spaces and interalveolar pores (pores of Kohn), and irregular thickening of alveolar septa around the small airway were observed. We, therefore, concluded that sidestream smoke induced an early phase of respiratory bronchiolitis, dilatation of respiratory bronchioles and alveolar ducts, and mild remodeling of pulmonary parenchymal structure.