| Objective: The pathological changes after hypoxic ischemic brain damage in the neonatal rat brain tissue to observe, to investigate the effect of erythropoietin(EPO) on hypoxic-ischemic brain damage(HIBD) mechanism affects the expression of neonatal rat Fas/fas L and erythropoietin EPO protective effect on hypoxic ischemic brain damage, for erythropoietin(EPO) to provide experimental and theoretical basis for the clinical treatment of neonatal hypoxic ischemic brain damage.Methods: Select 120 healthy newborn rats, which were randomly divided into sham operation group, ischemia group and EPO treatment group after hypoxia ischemia. The sham operation group without hypoxia treatment, was made in the rat model of hypoxic ischemic brain damage in HIBD group and EPO group. After EPO treatment group by intraperitoneal injection of 3000U/kg EPO, and the two groups were injected with sterile saline corresponding to 6h, 12 h, each group, 24 h, 48 h, 72 h 8 rats of each group were sacrificed after perfusion fixation, the brain tissue was taken conventional paraffin embedded sections, observe nerve cell morphology changes with HE staining, and immunohistochemistry expression chemical staining in three groups of rats at different time points of Fas and Fas L in the cerebral cortex. And the acquisition and analysis of images, each slice randomly selected 3 HPF(x 400), according to the determination of gray staining intensity of positive signal. The data were analyzed by using SPSS17.0 statistical analysis software, has adopted the normality test, variance analysis, q test, rank sum test and Pearson analysis and other statistical methods, P < 0.05 said the difference was statistically significant.Results:1 the changes of nerve function: the sham operation group had no obvious neurological abnormalities, the rats in group HIBD treatment groups were significantly different at each time point of the behavior score and the sham operation group and EPO(P<0.05), and with the extension of time and increased gradually, there is significant difference between EPO treatment group and sham operation in the 1H group, 2h, 4H(P<0.05), behavior score with time the behavior score decreased gradually, at several time points gradually with the sham operation group were similar, the difference was not statistically significant(P>0.05)2 to observe the pathological changes of brain tissue: the brain cortex of rats in the sham operation group the structure and cell level display is very clear; HIBD group of rats with hypoxic ischemic 6h, found that the neurons appear edema, hypoxia ischemia 12 h, structure of organelles in the neurons of different degrees of damage, hypoxia ischemia 24 h, focal necrosis occurred in brain tissue after hypoxic ischemia, 48 h, brain tissue can be seen in a wide range of tissue necrosis, neuronal cell nuclei in broken phenomenon, hypoxia ischemia 72 h, brain tissue can see clearly the boundaries of the nerve cell necrosis, near death state EPO; rats in the treatment group in the treatment of EPO after 6h, neuron structure is relatively fuzzy, EPO treatment of 12 h, neurons occurred mild edema, EPO treatment of 24h-48 h, nuclear membrane and nucleolus in neuronal cells were clearly visible nucleoli, deviated from the center position, EPO treatment of 72 h neurons, clear hierarchy, is located in the center of the nucleolus position.3 the expression of brain cells in rats at different time points of Fas: sham operation group at each time point were almost no obvious expression of Fas. In the HIBD group after hypoxia treatment 6h appeared Fas positive cells, and the expression of Fas increased with the duration of hypoxia, the expression of Fas reached the peak at 24 h, the expression of HIBD at each time point in group Fas compared with sham operation group, there was statistically significant(P<0.05). EPO expression in treatment group at the same time Fas was significantly lower than that in hypoxia ischemia group(P<0.05).4 the expression of brain cells in each group at different time points: Fas L is very similar with the expression of Fas Fas L in different groups. In the sham operation group, Fas L at each time point only a few expression. Fas L HIBD positive cells in group 6h after treatment began to hypoxia, increased with the duration of hypoxia, the expression of Fas L reached the peak at 24 h, the expression of HIBD at each time point in group Fas L compared with sham operation group, increased significantly(P<0.05). The expression of EPO in the treatment group at the same time Fas was significantly higher than that in the sham operation group(P<0.05), but significantly lower than that of HIBD group(P<0.05).Conclusions:1 at 6h after hypoxia ischemia, Fas synthesis in brain cells began to increase, reached the peak at 24 h, with the increase of Fas L protein expression gradually increased, peaked at 24 h, the expression of Fas before Fas L, and the positive correlation between the linear correlation analysis of the two, can activate the expression of it is concluded that Fas up-regulated Fas L protein protein.2 there is a direct relationship between Fas/Fas L and apoptosis of brain cells, is one of the pathogenesis of hypoxic ischemic brain damage.3 EPO can significantly reduce the expression of Fas and Fas L in brain tissue of HIBD in neonatal rats, and inhibition of apoptosis after hypoxia ischemia injury in brain tissue. |
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