Effects of radiation on nasal mucosa of guinea pig

Objective: To study histopathological changes in nasal mucosa of guinea pigs following a series of irradiation. Methods: A total of 60 healthy guinea pigs were divided into two groups randomly: the irradiation group (n=30) and the control group (n=30). The animals of the irradiation group were exposed nasally to linear accelerator X-rays at 5.0 Gy once a week for three weeks. At 1 d, 1 w, 2 w, 4 w, 10 w and half year after X-irradiation five animals per one group were sacrificed randomly, at each time point. Their middle nasal turbinate mucosa was observed under optical microscope and electron microscope, and were analysed by image analysis for histopathological transformation. Results: In the irradiation group, the early histopathological transformation was acute inflammatory reaction, at the fourth week the mucosa began to repair, which ended at the sixth month. But after repaired, some parts of the repaired mucosa were lined with squamous epithelium instead of the normal nasal mucosa. The rate of the cilia-covered area was only 52.9% at the sixth month. Conclusion: The nasal mucosa injury and the squamous metaplasia could form a pathological basis of dysfunction after irradiation