Departments of Neurology, Ruprecht-Karls-University Heidelberg, Germany.
Brain Res. 2011 Sep 30;1415:103-8. doi: 10.1016/j.brainres.2011.07.064. Epub 2011 Aug 6.
Oxygen therapy (OT) with hyperbaric oxygen (HBO) or normobaric hyperoxia (NBO) improves the oxygenation of penumbral tissue in experimental ischemic stroke. However, whether this results in the improvement of energy metabolism is unclear. We investigated the effect of both OTs on tissue acidosis and on ATP production. Beginning 25 min after filament middle cerebral artery occlusion (MCAO), mice breathed either air, 100% O₂ (NBO), or 100% O₂ at 3 ata (HBO) for 60 min. Regional tissue pH was measured using the umbelliferone fluorescence. Regional ATP concentration was depicted by substrate-specific bioluminescence. Severity of ischemia did not differ among groups in laser-Doppler flowmetry. Both NBO (70.1±14.0 mm³) and, more effectively, HBO (57.2±11.9 mm³) significantly reduced volume of tissue acidosis compared to air (89.4±4.0 mm³), p<0.05). Topographically, acidosis was less pronounced in the medial striatum and in the cortical ischemic border areas. This resulted in significantly smaller volumes of ATP depletion (77.8±7.7 mm³ in air, 61.4±15.2 mm³ in NBO and 51.2±14.4 mm³ in HBO; p<0.05). In conclusion, OT significantly improves energy metabolism in the border zones of focal cerebral ischemia which are the areas protected by OT in this model.
氧疗（OT）联合高压氧（HBO）或常压高浓度氧（NBO）可改善实验性缺血性卒中半影区组织的氧合作用。然而，这是否会导致能量代谢的改善尚不清楚。我们研究了这两种氧疗对组织酸中毒和 ATP 产生的影响。在栓线法大脑中动脉阻塞（MCAO）后 25 分钟开始，小鼠分别呼吸空气、100%氧气（NBO）或 100%氧气在 3 个大气压（HBO）下通气 60 分钟。使用伞形酮荧光法测量局部组织 pH 值。通过底物特异性生物发光法描绘局部 ATP 浓度。激光多普勒血流仪显示各组的缺血严重程度无差异。与空气组（89.4±4.0 mm³）相比，NBO（70.1±14.0 mm³）和更有效的 HBO（57.2±11.9 mm³）均显著降低了组织酸中毒的体积，p<0.05）。在组织学上，内侧纹状体和皮质缺血边界区的酸中毒程度较轻。这导致 ATP 耗竭的体积明显较小（空气组为 77.8±7.7 mm³，NBO 组为 61.4±15.2 mm³，HBO 组为 51.2±14.4 mm³；p<0.05）。总之，OT 显著改善了局灶性脑缺血边缘区的能量代谢，这是该模型中 OT 保护的区域。
