Apoptosis of neural cells in the neonatal rat cerebral cortex induced by 60Co Gamma Ray / 中华放射医学与防护杂志

ABSTRACT

Objective To identify the cell death type and investigate the potential mechanism of ionizing radiation-induced neural cell death in the neonatal rat cerebral cortex.Methods The neonatal Wistar rats were given a single dose of 2.0 Gy γ-irradiation.The cell death type and characterization in cerebral cortex were identified using DNA electrophoresis,TUNEL and HE staining.The P53-and iNOS-positive cells were analyzed quantitatively using immunohistochemistry.Results The DNA and morphological characterization of death cells indicated that 2.0 Gy γ-irradiation induced apoptosis of the neural cells in neonatal rat cerebral cortex.The apoptosis indices in different cortex regions were significantly increased 4 h after irradiation,and reached the peak value at 12 h post-irradiation.The apoptosis index of neoconex was much higher than that of hippocampus(archicortex)and paleocortex,while paleocortex had lower apoptosis index than hippocampus.The quantitative immunohistoehemistry suggested that the numbers of P53 and iNOS-positive cells were not different between these three cortex regions at the same time-point after irradiation.Conclusion 2.0 Gy γ-rays induced apoptosis of the neural cells in neonatal rat cerebral codex.The response of cells to the damage effects of ionizing radiation was similar in different cortex regions;however,the apoptosis indices were different significantly.These findings imply that the developing phase or type of neural cells may play a pivotal role in the apoptosis process induced by ionizing radiation.