Ultrastructural Examination of Early Changes of Small Airway and Pulmonary Parenchyma by Sidestream Cigarette Smoking

Keimyung Medical Journal 2001;20(2):188-198.

간접흡연에 의한 소기도 및 폐실질의 초기 변화에 관한 초미세형태학적 검색

권건영; 김영호; 이병육; 강유나; 이상숙

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.

Key Words: Sidestream smoke, Respiratory bronchiolitis, Alveolar epithelial and endothelial injury, Transmission and scanning electron microscopy