Ito T, Ikemi Y, Kitamura H, Ogawa T, Kanisawa M
Department of Pathology, Yokohama City University School of Medicine, Japan.
Exp Pathol. 1989;36(2):89-96. doi: 10.1016/s0232-1513(89)80120-3.
In order to assess the effect of prolonged inhalation of polluted ambient air on the respiratory tract, 30 Sprague-Dawley rats were kept in facilities built close to a street with heavy traffic in the City of Yokohama for 18 months in an atmosphere of either filtered (filtered group) or non-filtered polluted ambient air (exposed group), and the histology of the lung was examined. Scattered areas of chronic inflammation were seen from the nasal to bronchiolar mucosae in both the groups. Rats which inhaled the urban ambient air showed deposition of dust particles in the alveolar space and the peribronchiolar tissue, but no deposition was recognized in the filtered group. In both the filtered and exposed groups, papillary hyperplasia showing a positive immunoreaction to calcitonin was noted in the bronchobronchiolar epithelium. The hyperplasia was thus shown to have endocrine differentiation and this was considered to be pulmonary endocrine cell hyperplasia. In the exposed group, 2 bronchial papillomas were induced, and were shown to contain cells giving a positive immunoreaction to calcitonin. A histogenetical sequence was suggested in these 2 lesions because of their histological and immunohistochemical similarities.
为了评估长期吸入受污染的环境空气对呼吸道的影响，将30只Sprague-Dawley大鼠置于横滨市一条交通繁忙街道附近建造的设施中，在过滤后的（过滤组）或未过滤的受污染环境空气（暴露组）环境中饲养18个月，并对肺组织学进行检查。两组从鼻腔到细支气管黏膜均可见散在的慢性炎症区域。吸入城市环境空气的大鼠在肺泡腔和细支气管周围组织中可见尘埃颗粒沉积，但过滤组未发现沉积。在过滤组和暴露组中，支气管细支气管上皮均可见对降钙素呈阳性免疫反应的乳头状增生。因此，这种增生显示具有内分泌分化，被认为是肺内分泌细胞增生。在暴露组中，诱导出2个支气管乳头状瘤，且显示含有对降钙素呈阳性免疫反应的细胞。由于这2个病变在组织学和免疫组织化学上的相似性，提示了一个组织发生序列。
