Figure 2
Histopathological features associated with RILI in sheep. Panels (a–c) photomicrographs of an H&E-stained section illustrating the oedema that arises as a consequence of radiation exposure to the sheep lung. Oedema could be appreciated macroscopically (a) and was frequently found in the subpleural region (scale bar 5 mm). The borders between areas of oedema and aerated lung were often sharply demarcated (b) (scale bar 1 mm). Perivascular oedema was also recognised (c) (scale bar 100 μm). Panels (d–f) photomicrographs of picrosirius red-stained sections highlighting collagen deposition. Panels (e) and (f) are section images from radio-exposed lung (scale bars 100 and 50 μm respectively) and (d) from the contralateral control lung (scale bar 100 μm). Radiation exposure was associated with an increase in the area percentage of collagen. Panels (g–i) photomicrographs highlighting the expression of ASMA in radio-exposed lung (h and i, scale bars 250 and 50 μm respectively), and from the contralateral control lung (g) (scale bar 250 μm). ASMA expression in the non-radio-exposed lung was sparse and found in association with the alveolar ducts, both at the septal tips and in the alveolar walls. Radiation exposure led to an increase in ASMA expression in these areas.
