아황산가스가 흰쥐 허파조직내 Laminin 활서에 미치는 영향에 대한 면역조직학적 연구 = The Immunohistological Study on the Expression of Laminin in Lung from Sulfur Dioxide-exposed Rats

다국어 초록 (Multilingual Abstract)

Sulfur dioxide (SO_2), a kind of air pollutant, causes harmful damage to human body. In particular, inhalation of sulfoxide dioxide has been demonstrated to result in the injury to the upper respiratory duct. However, mechanisms by which SO_2 affects these tissues remain to be clarified. In the present study, to investigate the mechanism of SO_2 effects, the influence of SO_2 exposure was examined in terms of the injury of lung and the expression pattern of laminin in the basal lamina. The basal lamina is an important tissue for the regulation of internal respiration by composing of air-blood barrier.
Sprague-Dawley rats repetitively exposed to a mixture of O_2 gas and SO_2 gas (250 ppm) for 30 minutes a day were sacrificed to observe the distribution of laminin in the alveolar septum as well as the morphological alteration of alveoli using immunohistological methods.
The resutls we observed were as follows:
1. Alveoli from SO_2-exposed rats (for 5 days) were strongly stained with anti-laminin antibody, suggesting laminin expressed at the high level, at week 1 to 3 upon exposure to SO_2
2. At week 1 to 3 after exposure of rats to SO_2, alveolar septa were collapsed, leading to the reduction of alveolar volume along with morphological changes to irregular shapes.
3. At week 4 to 6 after exposure of rats to SO_2, alveoli were weakly stained with anti-laminin antibody, suggesting laminin expression was decreased during this period.
4. Rats sacrificed at week 7 upon exposure to SO_2 exhibited the expansion of new alveoli and the expression of laminin was partially recovered up to the intermediate level.
Taken together, these results demonstrate that the expression of laminin was enhanced in the early phase, followed by downregulation in the late phase. Moreover, lung injury and resolution were correlated with the level of laminin. Thus, these results suggest that SO_2 suppresses the expression of laminin, which may be associated with the neo-generation of lung tissue.