高压氧促进缺氧缺血性脑损伤新生大鼠内源性神经干细胞增殖的时间窗研究

目的：探讨高压氧（HBO）治疗是否可以促进缺氧缺血性脑损伤（HIBD）新生大鼠内源性神经干细胞（NSC）的增殖及HBO治疗HIBD的时间窗。方法：采用Rice法制成HIBD模型,分别于HIBD后第3、6、12、24和72h开始给予HBO治疗,1次/d,连续7 d。HIBD后10 d,BrdU/Nestin免疫荧光双标法检测不同时间窗HBO治疗对内源性NSC的影响,Western blot法检测Nestin蛋白的表达;HIBD后28 d尼氏染色法检测海马CA1区锥体细胞密度。结果：HIBD后3、6、12和24 h给予HBO治疗,侧脑室室管膜下（SVZ）区BrdU＋Nestin＋细胞显著增加（P〈0.05）,损伤侧大脑Nestin蛋白表达显著高于HIBD组（P〈0.05）;尼氏染色结果显示HIBD后3、6、和12h给予HBO治疗,海马CA1区神经元丢失较HIBD组显著减少（P〈0.05）。结论：HBO治疗可以促进HIBD新生大鼠内源性NSC的增殖,治疗时间窗拓宽至HIBD后24 h可促进NSC增殖,HIBD后72 h进行HBO治疗则疗效不显著。

Therapeutic windows of hyperbaric oxygen for promoting neural stem cell proliferation in hypoxic-ischemic neonatal rats

Objective: To explore the effect of hyperbaric oxygen(HBO) in promoting the proliferation of neural stem cells(NSC) in neonatal hypoxic-ischemic rats and its therapeutic window for hypoxic-ischemic brain damage(HIBD).Methods: Seven-day-old Sprague-Dawley rats were subjected to the Rice procedure.Hyperbaric oxygen therapy was applied 3,6,12,24 and 72 h after HIBD,once daily for 7 consecutive days.5-bromo-2'-deoxyuridine was examined by immunofluorescence and nestin was detected by Western blotting analysis 10 days after HIBD.Cerebral morphology was examined by Nissl staining 28 days after HIBD.Results: There were remarkable increases in neural stem cell proliferation and Nestin protein expression in the HBO groups treated 3,6,12 and 24 h after HIBD in comparison with the non-HBO groups.The HBO groups treated within 12 h after HIBD had less neural loss in the hippocampal CA1 region as compared with the non-HBO HIBD groups.Conclusion: Hyperbaric oxygen therapy can stimulate the proliferation of neural stem cells and the therapeutic window for HBO treatment could be extended to 24 h after HIBD,but the effect does not seem satisfactory when the therapeutic window is delayed up to 72 h after HIBD.