高压氧反复暴露对小鼠脑内促红细胞生成素含量的影响

Effect of repeated hyperbaric oxygen exposures on erythropoietin concentration in mice brain

目的通过对脑内促红细胞生成素(EPO)的检测,探讨高压氧(HBO)反复暴露增强低氧耐受能力是否与EPO有关。方法昆明小鼠54只,随机分为3组:(1)HBO组:实验动物置密闭氧舱内供给医用纯氧,每天2次,每次60 min,连续3 d。供气压力第1-3天分别为150,200和250 kPa(绝对压);(2)高压空气(HPA)组:舱内供给常氧氮混合气,其他处理同HBO组;(3)空白对照(NC)组:仅在每天同一时间模拟进出舱活动,不作其它处理。处理结束后24 h,①将每组10只动物同时置密闭氧舱内,进行低氧耐受实验。舱内持续供给5％O2-95％N2混合气体,压力为常压,记录每只动物在常压低氧状态下的生存时间;②同时将每组8只动物分别按实验要求取材,用免疫组化法检测各组动物脑内 EPO阳性细胞表达情况。结果低氧生存时间测定结果表明,HBO组低氧生存时间较其它两组明显延长。免疫组化结果显示,与NC组相比,HPA组脑内各脑区EPO阳性细胞数均未发现明显改变;与HPA 组相比,HBO反复暴露3 d后,小鼠脑内EPO阳性细胞数发生明显改变,大脑皮层和海马EPO阳性细胞数显著增多。结论 HBO反复暴露能增加小鼠低氧耐受能力;HBO反复暴露能增加小鼠脑内EPO含量,这可能是HBO反复暴露增强动物低氧耐受能力的重要机制之一。

Objective To observe the effect of repeated hyperbaric oxygen on erythropoietin （EPO） production in mice brain. Methods 54 Kunming mice were randomly distributed into 3 groups： hyperbaric oxygen （HBO） group,high pressure air （HPA） group and naive control （NC） group. In the HBO group,mice were exposed to pure oxygen for 60 mins twice a day for 3 consecutive days. Pressures from the first to the third day were 150 kPa,200 kPa and 250 kPa respectively. And mice in the HPA group were exposed to compressed air for 60 min at the same pressure as the HBO group twice a day 3 consecutive days. 24 h after exposure, mice survival time during normobaric hypoxia was tested in every group. The expression of EPO protein in the cerebral cortex and hippocampus of micebrains was determined by immunohistochemistry （IHC） （8 mice per group）. Results Compared with NC group, survival time during hypoxia was prolonged in the HBO group （ P 〈 0. 05）. The production of EPO in hippocampus and cerebral cortex in the HBO group was significantly increased, compared witb the NC group （ P 〈 0. 01, 〈 0. 05 ）. Conclusions Hypoxia tolerance can be induced by HBO. And repeated exposure to HBO can increase the production of EPO in mice brains, which may be one of the reasons for hypoxia tolerance induced by HBO exposure.