Fundamental study for development of a new preventive method of radiation pneumonitis

本研究旨在通过大鼠实验系统研究螺内酯对放射性肺损伤的抗纤维化作用。雌性Wistar大鼠用200kVp X线照射右侧全胸，剂量为15Gy。90-在照射之前或之后，将200mg螺内酯的日释放小丸皮下植入大鼠的左背部。照射后13周，处死大鼠，取出双侧肺并固定在缓冲甲醛中用于组织病理学检查。评价每个肺的纤维化变化和泡沫状巨噬细胞浸润。在照射前给予螺内酯，照射后肺纤维化改变更明显。如果螺内酯给药延迟照射后，纤维化的变化并没有抑制螺内酯。不同给药时间组的泡沫巨噬细胞浸润无显著差异。

The purpose of this study was to reveal the anti-fibrotic effect of spironolactone after pulmonary irradiation by an experimental system of rats. Female Wistar rats underwent local irradiation of the right whole thorax with a single dose of 15Gy by 200kVp x-rays. 90-day release pellets of 200mg of spironolactone were implanted in the rat's left back subcutaneously before or after irradiation. 13 weeks after irradiation, rats were sacrificed and bilateral lungs were removed and fixed in buffered formaldehyde for histopathological examinations. Fibrotic changes and foamy macrophage infiltrations were evaluated for each lung. The fibrotic changes of the irradiated lungs were severer when spironolactone was administered before irradiation. If spironolactone administration was delayed after irradiation, fibrotic change was not suppressed by spironolactone. Foamy macrophage infiltrations were not significantly different among the groups of different timings of spironolactone administration.