高压氧预适应对大鼠高原颅脑损伤的作用研究

目的探讨高压氧（HBO）预适应对高原颅脑损伤（TBI）的神经保护作用。方法将78只SD大鼠随机分为平原组、高原组和高压氧预适应组，各组按Feeney自由落体撞击法制作TBI模型，并通过低压氧舱模拟高原环境。采用Longa评分法进行神经功能缺损评分，Moor DRT4激光多普勒血流监测仪和LICOX CMP组织氧分压监测仪分别监测伤区局部脑血流（rCBF）和局部脑组织氧分压（PbtiO2）变化，利用光镜观察伤区脑组织的病理学改变。结果伤后24h高原组较平原组神经功能缺损评分上升。rCBF和PbtiO2下降，病理损伤加重；高压氧预适应组较高原组神经功能缺损评分下降（P〈0.05），rCBF和PbtiO2升高（均为P〈0.05）病理损伤减轻。结论高压氧预适应可诱导对高原颅脑损伤的神经保护作用改善神经功能。

Effects of hyperbaric oxygen preconditioning on traumatic brain injury at simulated high altitude in rats

Objective To investigate the neuroprotective effects of hyperbaric oxygen (HBO) preconditioning on traumatic brain injury (TBI) at simulated high altitude in rats. Methods Seventy-eight rats were divided into three groups: the plain group, high altitude group and HBO preconditioning group. The TBI models were produced by dropping weight. The high altitude environment was simulated with a hypobaric oxygen chamber. The nerve function was scored by Longa scale. The regional cerebral blood flow (rCBF) was recorded with a laser-Doppler flowmeter and the pressure of brain tissue oxygen (PbtiO2) was monitored with LICOX CMP monitor. The pathological changes of the brain tissue in the injured region were observed under light microscope. Results The Longa score was increased, the rCBF and PbtiO2 were decreased and the pathological changes aggravated 24 hours after injury in the high altitude group compared with the plain group. In the HBO preconditioning group, the Longa score was decreased, whereas the rCBF and PbtiO2 were higher than those in the high altitude group 24 hours after injury (P<0.05). The pathological changes were lighter in the HBO preconditioning group than in the high altitude group. Conclusion HBO preconditioning can produce neuroprotective effects on TBI at simulated high altitude, and improve the neurological functions.