[Changes in type II alveolar epithelial cells in experimental allergic alveolitis]

Changes of type II alveolar epithelial cells (type II cells) were studied in experimental allergic alveolitis by using enzyme histochemical, electron microscopic and morphometric techniques. The results showed that the number of type II cells increased obviously after exposed to thermoactinomyces vulgaris (TV). The peak was on the 15th day and then decreased gradually till to normal on the 180th day. Type II cells could be divided into two populations in TV-treated rats, namely, the large type II cells and the small type II cells. The former ones bore a diameter larger than the value of mean + 2.58s and mean indicated the mean value of type II cells diameters of the controls. The large type II cells are known to be the hypertrophic cells.