不同氧浓度复苏对创伤性轴索损伤合并低氧血症后大鼠脑组织的影响

目的 在创伤性轴索损伤（traumatic axonal injury,TAI）合并低氧血症性二次脑损伤（secondary brain injury,SBI）大鼠模型基础上进一步探讨不同氧浓度复苏对大鼠脑组织病理学的影响.方法 应用自制TAI致伤装置,大鼠伤后给予10％浓度氧吸入30min制成低氧血症性SBI模型,随后给予大鼠不同氧浓度混合气体1h,复苏后不同时间点（24h、1周）进行免疫组化染色.结果 脑干ROI的β-APP免疫组化染色显示,24h时TAI合并缺氧组的阳性染色明显强于各复苏组,50％氧浓度时的阳性染色最弱;各组阳性染色随时间而减弱,1周时各组阳性染色明显弱于24h,此时TAI合并缺氧组的阳性染色仍明显强于各复苏组,50％氧浓度时的阳性染色最弱.染色阳性的神经轴索半定量分析显示,24h时TAI合并缺氧组明显高于各复苏组,50％氧浓度时的值最低;各组数值随时间而降低,1周时各组值明显低于24h,此时TAI合并缺氧组的值仍高于各复苏组,50％氧浓度的值仍为最低.结论 给氧治疗可以显著减低轴索损伤,起到神经保护作用;对于当前的TAI合并缺氧动物模型的最佳复苏氧浓度为50％.

Effect of Different Oxygen Concentration on the Brain Tissue of Post-Traumatic Axonal Injury with Hypoxia

Objective To explore the effects of different oxygen concentrations on the brain tissue in the hypoxia-induced secondary brain injury（SBI） rat subjected to traumatic axonal injury（TAI）.Methods TAI and systemic hypoxia was induced by an impact-acceleration ＆ rotation device and ventilating rats with 10% oxygen in nitrogen 30min,respectively.After that the rats were given different concentrations of oxygen gas mixture 1 hour.Immunohistochemistry staining among those groups were systemically assessed and compared.Results Beta-APP immune staining in brainstem ROI showed that when 24h positive staining of TAI and hypoxia group was stronger than the resuscitation groups.When 50% oxygen concentration the positive staining was the weakest.The positive staining decreased over time.and 1 w positive staining was weaker than that in 24h.The positive staining of TAI combined with hypoxia group was obvious stronger than the recovery groups,and the positive staining in 50% oxygen concentration was the weakest.Positive staining of axonal semi quantitative analysis showed that,it was significantly higher in 24h TAI combined with hypoxia group than that of the resuscitation groups,with minimum value of 50% oxygen concentration.Numerical groups decreased with time,and 1 w value of each group was significantly lower than that in 24h.Values in the TAI combined hypoxia group were still higher than the resuscitation groups,and 50% oxygen concentration values still was the lowest.Conclusion Oxygen therapy can significantly reduce axonal injury,thus play a neuroprotective role.For the best recovery to TAI combined with hypoxia in the current animal model,the oxygen concentration is about 50%.