缺氧诱导大鼠脑细胞低氧诱导因子-1α表达的研究

Expression of hypoxia inducible factor -1α in brain of rats during hypoxia

目的 观察低氧条件下大鼠脑细胞中低氧诱导因子 - 1α(HIF- 1α)的表达情况 ,探讨缺氧脑损伤可能的机制。方法 建立常压状态下缺氧动物模型。急性缺氧模型 :将大鼠置于 5± 0 .5 %氧浓度的低氧舱中 1.5 h;慢性间断性缺氧模型 :将大鼠置于 10± 0 .5 %氧浓度的低氧舱中 6 h/ d,6 d/周 ,共 4周。应用免疫组化法检测脑 HIF- 1α表达。结果 急性及慢性间断性缺氧后大脑变性神经元增加 ,同时 ,HIF- 1α免疫阳性神经元数目明显增多 ,主要分布在海马及下丘脑。结论 缺氧可诱导 HIF - 1α在大脑神经元中的表达。 HIF- 1α可能参与了缺氧性脑损伤过程。

Objective To evaluate the expression of hypoxia inducible factor 1α (HIF 1α) and to explore its possible roles in the established models of acute and chronic cerebral hypoxia. Methods The Sprague Dawley rats were placed in a hypoxia chamber with 10% O 2 or 5% O 2. Hypoxia was maintained by infusing N 2 to balance against an inward leak of air through holes in the chamber. The rats were divided into two groups: acute hypoxia group and chronic hypoxia group.The rats of acute hypoxia group were placed in the hypoxic chamber for 1.5 hours while the chronic hypoxic rats were exposed to 6 hours of hypoxia daily (6 days/week,4 weeks). Immunocytochemistry was performed to detect the expression of HIF 1α in brain after acute and chronic hypoxia. Results HIF 1α positive neurons were detected at 4 hours and disappeared at 9 hours after 1.5 hour of hypoxia. More HIF 1α neurons were seen after 4 weeks of hypoxia. These neurons were mostly distributed in the hippocampus and hypothalamus, occasionly in the cortex. Conclusion The expression of HIF 1α is increased in brain on the hypoxia condition, which indicates that HIF 1α may play an important role in the pathogenesis of hypoxic cerebral injury .