Radiation Brain Injury Pathogenesis And Traditional Chinese Medicine Research Areas,

Objective: To observe the apoptosis in the hippocampal neurons, microvessel density(MVD) in the white and gray matters and correlative gene expression after whole brain irradiation in mice. To explore the mechanism of radiation brain injury and the effect of traditional Chinese medicine (978-1 and Salvia Miltiorrhiza) on radiation brain injury.Materials and methods: 6MV-X ray was used to irradiate the whole brain of BALB/C male mice to establish the brain injury model. Mice were randomly assigned into 30Gy, 20Gy, 20Gy plus 978-1, 20Gy plus Salvia Miltiorrhiza, 10Gy and control groups. Hematoxylin-eosin(HE), Immunohistochemistry(IHC) stains, electron microscope and flow cytometry(FCM) analysis were used to detect the apoptotic index(AI), P53, Bcl-2 and Bax: expression in the hippocampal neurons after whole brain irradiation at 3, 6, 12, 24, 48 and 72 hours; MVD, vascular endothelial growth factor(VEGF) and basic fibroblast growth factor(bFGF) expression on 1, 2, 3, 7, 14, 28, 56 and 84 days. The changes of the body weight and the learning and memory ability by step down method were observed.Results: The apoptosis had typical morphological characteristic in the hippocampal neurons. The apoptosis began to rise at 3 hours after irradiation, peaked at 6 hours and recovered at 24 hours. The maximum AI with 30, 20 and lOGy groups were 5.0%, 3.7% and 2.8%, respectively(P<0.01). There were no apoptosis in control groups. The expression of p53 in the hippocampus neuronal nucleus began to rise at 3 hours after irradiation, peaked at 6 hours and recovered at 24 hours. The expression of Bcl-2 and Bax were no change. In irradiation groups, the hippocampal neurons were shrunken with irregular shape, the blood vessel wall thickening and luminal occlusion; the MVD began to decrease more significantly in white matter in 20Gy group than in...