Observation On The Microvascular Casting Of Guinea Pig Nasal Mucosa Irradiated By Scanning Electron Microscopy And Determination Of Immunoglobulin A,CD3 T Lymphocytes In The Nasal Mucosa

Subject: To observe the damage of radiation in the nasal mucosa of the guinea pig by the microvascular corrosion casts and scan electron microscope, and to observe change of immunoglobulin A and CD3T lymphocytes in the nasal mucosa, study the mechanism of damage of radiation and the impact of local immune function of nasal mucosa.Methods: Totally, eighty-four health guinea pigs were used and divided into two groups randomly: the control group, including twelve guinea pigs, the irradiated group, including seventy-two guinea pigs. The control group did not be irradiated, six guinea pigs were chosen randomly to make microvascular corrosion casts, the other six were explored by immunohistochemistry to detect the expression of immunoglobulin A and CD3 T lymphocytes in the microcirculation of nasal mucosa. The experimental groups were irradiated by the WDVE—6MeV linear accelerator, giving 5 Gy one time one week for three weeks through X-ray irradiating to establish the animal irradiation injury model. Then, after having been irradiated, twelve animals were killed respectively for half month, one month, two months, three months, five months and six months. Six guinea pigs were chosen randomly to make microvascular corrosion casts, the other six were studied by immunohistochemistry to detect the expression of immunoglobulin A and CD3 T lymphocytes. Results: (1) The early histopathology transforms of the irradiated group was acute inflammatory reaction, inflammation cells infiltrating in the submucosa, nasal mucosa tissues congesting, partial nasal mucosa necrosis or shedding. The acute inflammatory reaction declined as the time went by. Then, the nasal mucosa repaired step by step. But parts of the area were squamous epithelium instead of the normal ciliary structure. (2) Through scan electron microscope , a series of changes of irradiated damage can be found . In the early, the capillary expanded and congested, the vascular endothelial cell swelled. Later, the capillary became deformation and tore. These irradiated damage worsen obviously as the time went by, microvascular networks broke off after radiation and the number of capillary reduced, which led to capillary density descended. Although partial area had new capillary, the structure became disordered and no microcirculation functioned. (3) At the same time, it was found that the number of CD3 T cells markedly increased at the early time, later, the number of CD3 T cells decreased gradually. However, immunoglobulin A in the nasal mucosa was always decreasing, this phenomenon showed that local mucosa immune function was suppressed after radiotherapy. Conclusion: The early histopathology transforms of the irradiation injury was acute inflammatory reaction, partial mucosa necrosised or shed. Then the mucosa repaired step by step, but parts of the area were squamous epithelium instead of the normal ciliary structure. Radiation can damage the vascular system, results in damages such as vascular endothelial degeneration, capillary narrowing, partial or total disconnection of microvessels, small veins shrinking, and presence of vessel- disappeared area. these result in abnormality of tissue microcirculation. It was also found that the number of CD3 T lymphocytes markedly increased at the early time after radiation; later, the number of CD3 T cells decreased gradually. However, immunoglobulin A in the nasal mucosa decreased gradually, this showed that the mucosa immune function was damaged. From the results of experiments, it was suggested that radiation suppressed not only the general immune function but also the local nasal mucosa immune function.