高压氧预处理对新生大鼠脑缺血损伤的保护作用

Protective effect of hyperbaric oxygen pre-treatment on hypoxic-ischemia brain damage in neonatal rats

目的观察高压氧预处理后缺氧缺血型脑损伤（hypoxia—ischemia brain damage，HIBD）新生大鼠脑组织神经干细胞增殖变化以及后期脑发育和功能。方法将6日龄新生大鼠进行0．25MPa高压氧预处理150min，24h后制作HIBD模型，然后暴露于8％氧、92％氮的混合气中90min。观察皮层和海马神经干细胞的增殖情况、损伤后大鼠体质量增长率和成年后脑形态，水迷宫检测学习记忆功能。结果高压氧预处理组神经干细胞增殖显著，发育情况、脑形态和学习记忆功能与HIBD组有显著差异。结论高压氧预处理可能通过促进神经干细胞增殖发挥对新生大鼠HIBD的保护作用并影响后期脑发育。

Objective To investigate the effect and mechanism of hyperbaric oxygen （ HBO ） on hypoxic-ischemia brain damage （HIBD）in neonatal rats. Methods Neonatal SD rats were pre-treated by means of hyperbaric oxygen exposure at a pressure of 0.25 MPa for 150 min. Following treatment after 24 hours, HIBD model was developed by the occlusion of left carotid artery, and then the animals were exposed to a mixture of 8% oxygen and 92% nitrogen for 90 min. Assessment of neural stem cells （NSCs） in the brain tissue was made with immunohistochemistry. Observation on the proliferation of neural stem cells in cortex and hippocampus, rate of increase in body weight and cerebral morphology after adulthood was also made following injury. Learning and memory of the animals were determined with labyrinth. Results Proliferation of neural stem cells increased dramatically for the animals in the hyperbaric oxygen group. Significant differences could be noted in development, cerebral morphology, learning and memory, when compared with those of the HIBD animals without HBO treatment. Conclusions Hyperbaric oxygen pre-treatment might have certain protective effect on HIBD in neonatal rats, possibly through the proliferation of NSCs and might also influence cerebral development at later stages.