Training the Brain to Survive Stroke
Training the Brain to Survive Stroke
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DOI：
10.1371/journal.pone.0045108
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发表时间：
2012-09-13
期刊：
影响因子：
3.7
通讯作者：
Natah, Sirajedin S.
中科院分区：
文献类型：
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作者：
Dunn, Jeff F.;Wu, Ying;Natah, Sirajedin S.
背景：目前，几乎没有什么可以修复脑组织中风后的损害。我们假设哺乳动物大脑具有适应低氧的内在能力，这将改善可逆性缺氧/缺血发作的结果。适应慢性缺氧导致毛细血管和组织氧水平增加，这可能提高缺血存活的能力。识别这些适应将导致协议的高风险群体可以使用，以提高恢复和降低costs.Methods和调查结果：大鼠暴露于缺氧（3周生活在K的气氛）。适应后，毛细血管密度的形态测定和增加了30%的皮质。新的植入式氧传感器显示，大脑中的氧分压在正常皮层中增加了40%。用可逆性大脑中动脉闭塞1小时在脑中诱导脑梗死。缺血后（48小时）的行为评分得到改善，T2加权MRI病变体积减少了52%，在适应组。淋巴细胞减少（减少27-33%）和ED 1阳性细胞减少（减少35-45%）表明炎症减少。结论：刺激大脑中的自然适应机制是可能的，这将减少损伤并改善给定缺血事件的结果。由于这些适应发生在HIF-1 α等因子恢复到基线水平之后，因此保护可能更多地与血管生成等形态学变化有关。这样的预处理，也许是运动或药物，不一定会降低中风的发生率，但损害的严重程度可以降低50%。
Background: Presently, little can be done to repair brain tissue after stroke damage. We hypothesized that the mammalian brain has an intrinsic capacity to adapt to low oxygen which would improve outcome from a reversible hypoxic/ischemic episode. Acclimation to chronic hypoxia causes increased capillarity and tissue oxygen levels which may improve the capacity to survive ischemia. Identification of these adaptations will lead to protocols which high risk groups could use to improve recovery and reduce costs.Methods and Findings: Rats were exposed to hypoxia (3 weeks living at K an atmosphere). After acclimation, capillary density was measured morphometrically and was increased by 30% in the cortex. Novel implantable oxygen sensors showed that partial pressure of oxygen in the brain was increased by 40% in the normal cortex. Infarcts were induced in brain with 1 h reversible middle cerebral artery occlusions. After ischemia (48 h) behavioural scores were improved and T2 weighted MRI lesion volumes were reduced by 52% in acclimated groups. There was a reduction in inflammation indicated by reduced lymphocytes (by 27-33%), and ED1 positive cells (by 35-45%).Conclusions: It is possible to stimulate a natural adaptive mechanism in the brain which will reduce damage and improve outcome for a given ischemic event. Since these adaptations occur after factors such as HIF-1 alpha have returned to baseline, protection is likely related more to morphological changes such as angiogenesis. Such pre-conditioning, perhaps with exercise or pharmaceuticals, would not necessarily reduce the incidence of stroke, but the severity of damage could be reduced by 50%.