実験的耳管狭窄における中耳病変

抄録

Electron irradiation was done to the pharyngeal orifice of the eustachian tube in guinea pig to observe the pathological change of middle ear structures followed by tubal dysfunction. 2000 rads alone, 2000 rads × 2 (with one month interval), 3000 rads, 3000 rads × 2 (with one month interval) and 3000 rads + 1000 rads × X (with 2 weeks' intervals) were irradiated respectively and pathological changes of the middle ear structures using H-E staining were observed 1 week, 2 weeks, one month, 2 months after the cessation of irradiation. The results obtained were as follows. Early changes, i. e., one or two weeks postirradiation consist of thickening of submucosal connective tissue layer and infiltration of inflammatory round cells. At the mid-stage post irradiation, i. e., one month later, cuboidal and columnar changes in epithelial layer appeared. At the same time connective tissue layer was more thickened with numerous fibroblasts. Occasionally osteoclast and osteoblast were found beneath the periosteum. At the final stage in our series, i. e., two months postirradiation, new bone formation and remodelling became obvious with occasional fat degeneration.