Study On Vascular Endothelia Cell Injury And Radiation-induced Lung Injury

OBJECTIVE:To investigate the mechanisms of radiation-induced lung injury based on vascular endothelial cell injury.METHODS AND MATERIALS:Wistar 75 rats were irradiated to the right hemithorax with a single dose of OGy,7.0Gy,14.4Gy. Serial studies were performed before and 1,7,30,90,180 days after irradiation. Histological studies were carried out to detect histological changes in the pulmonary after irradiation. Immunohistochemistry assay was to detect the expression of CD34,CD105,VEGF,FⅧ:RAg.RESULTS:In control group and 7.OGy groups, there were no notable hispathological changes, just including little tissue exudates, congestion, edema and infiltration of inflammatory cells, red blood cell leakage. However, the inflammation was more obviously and the formation of collagen and fibrosis could be observed in 14.4Gy group. Compared with the control group, there was no difference of the expression of CD34 in 7.OGy group.However, there was statistically significant in 14.4Gy group except one days. The expression of CD105 were not statistically significant in 7.OGy group. However, only 7 days to 30 days has statistical significance in the 14.4Gy group. The expression of VEGF was negative in control and 7.OGy group. The expression of VEGF had statistical significance at 30 days later.The expression of FⅧ-RAg were not statistically significant difference in 7.0Gy group. Otherwise, there was statistically significant in 14.4Gy group at all time points.Conclusion:when Lung tissue radiation injury, microcirculation in mature endothelial cell number was persistently reduced, it may be the key cause of new capillary angiogenesis disorders and chronic fibrous repair.