高压氧治疗对缺氧缺血性脑损伤新生大鼠内源性神经干细胞增殖的影响

The promoting effect of hyperbaric oxygen on the proliferation of endogenous neural stem cells in neonatal rats with hypoxic ischemic brain damage

目的探讨高压氧（HBO）治疗缺氧缺血性脑损伤新生大鼠后，内源性神经干细胞增殖的动态变化。方法将7日龄Sprague—Dawley新生大鼠随机分为正常对照组（对照组）、缺氧缺血脑损伤组（模型组）与HBO治疗组（HBO组）。采用经典的Rice-Vannucci法制作缺氧缺血性脑损伤模型，HBO组在脑损伤后3h内进行HBO治疗，治疗压力为2个绝对大气压，稳压60min，每日1次，连续7d。分别于HBO治疗后第3小时、第21小时、第3天、第7天和第14天，采用5-溴-2-脱氧脲苷（BrdU）／巢蛋白免疫荧光双重标记法动态检测缺血侧侧脑室室管膜下区与海马齿状回内源性神经干细胞增殖的动态变化；采用Western blot法检测缺血侧大脑半球巢蛋白的动态变化。结果HBO组室管膜下区与海马齿状回BrdU^＋／巢蛋白标记的神经干阳性细胞数分别于HBO治疗后第3小时及第21小时显著增加，第7天达最高水平，并显著高于模型组和对照组（P〈0．01），第14天BrdU^＋／巢蛋白阳性细胞数开始下降，仍高于模型组和对照组（P〈0．01）；巢蛋白的Western blot分析发现，缺血侧大脑半球巢蛋白于HBO治疗后第21小时开始增加，第7天达峰值后下降。结论缺氧缺血性脑损伤后3h内给予HBO治疗，可以促进缺氧缺血性脑损伤新生大鼠内源性神经干细胞的增殖。

Objective To study the effect of hyperbaric oxygen （HBO） therapy on changes in the proliferation of endogenous neural stem cells （NSCs） in neonatal rats after hypoxic ischemic brain damage （HIBD）. Methods A total of 150 Sprague-Dawley rats aged 7 d were randomly divided into a normal control group （CON） , a HIBD group and a HBO treatment group. HBO was administered to the HBO treatment group within 3 h after HIBD at 2 atmospheres, once daily for 7 d. The HIBD model rats were subjected to unilateral carotid artery ligation followed by 2 h of hypoxia （8% O2 ）. BrdU/nestin immunofluorescence was used to examine the proliferation of NSCs dynamically in the subventricular zone （SVZ） and the dentate gyrus （DG） at the 3rd h, 21st h, 3rd d, 7th d and 14th d after HBO therapy. Nestin protein was detected by Western blot analysis at various time points after HIBD. Results In the HIBD rats treated with HBO, proliferation of endogenous NSCs was observed in the SVZ and DG. The proliferating NSCs increased at the 3rd h and 21st h after HBO therapy in the SVZ and DG respectively, peaked at the 7th d after HBO therapy, and decreased by the 14th d after HBO therapy, though their level was still higher than that in the controls. The Western blot analysis showed that nestin protein began to increase at the 21st h after HBO therapy, peaked at the 7th d after HBO therapy, then decreased. Conclusion HBO administered within 3 h after HIBD can promote proliferation of endogenous NSCs in neonatal rats after HIBD.