金刚烷胺对缺血缺氧脑损伤新生鼠的脑保护作用及其机制

Neuroprotective Effects of Amantadine on the Hypoxic-ischemic Brain Injury of Neonatal Rats

目的探讨非竞争性N-甲基-M-天冬氨酸(NMDA)受体阻断剂金刚烷胺(amantadine,AMA)对缺血缺氧脑损伤新生鼠的治疗作用及可能的作用机制。方法 7d龄的新生SD大鼠结扎右侧颈总动脉,随后吸入8%O22h,建立新生鼠缺血缺氧性脑病(HIE)模型。实验动物分为3组:空白对照组(n=15)、模型(HIE)组(n=15)和治疗(AMA)组(n=45),治疗组分为3个亚组,每组15只,分别于术前30min,术后15min和低氧吸入前30min给予鼻腔注入AMA 50mg/kg体重。术后7d取双侧大脑称重,通过右/左侧大脑半球重量比测定筛选出1个亚组的给药时点作为后续实验的给药时点。另取大鼠45只,模型制作和分组同前(每组15只),术后24h取结扎侧海马,采用ELISA方法测定IL-1β和IL-6的浓度。另取大鼠45只,模型制作和分组同前(每组15只),术后30d进行行为学测试,包括大鼠钻洞实验、转动杆测试和恐惧实验,比较各组差异。结果术后15min给予AMA可提高大鼠右/左侧大脑半球重量比,与HIE组相比,差异有统计学意义(P<0.05)。与HIE组比较,术后15min给予AMA不仅可降低结扎侧海马的IL-1β、IL-6浓度,而且可减少钻洞时间,延长转动杆站立时间和恐惧记忆时间,差异均有统计学意义(均P<0.05)。结论 AMA可减轻缺血缺氧后新生鼠的海马炎症反应,降低脑损伤,提供脑保护作用。

Objective To examine the neuroprotective effects of amantadine（AMA）,a non-competitive NMDA receptor an-tagonist,on the hypoxic-ischemic（HI）brain injury of neonatal rats and the possible mechanisms.Methods Hypoxic-ischemic encephalopathy（HIE）models were established in seven-day-old male and female Sprague-Dawley rats by ligating the right ce-phalic artery and then inhaling 8% oxygen for 2 h.All the rats were divided into 3 groups：control group（n=15）,HIE group（n=15）,and AMA group（n=45）.Animals in AMA group were intranasally treated with AMA at 50 mg/kg 30 min before and 15 min after ligation and 30 min before inhalation（15 rats each used at the three time points）.The right-to-left hemispheric weight ratio was calculated 7 days after the HI brain injury.The right hippocampus tissues of rats（n=45）were harvested 24 h after the HI brain injury and the concentrations of IL-1βand IL-6 were detected by ELISA.The outcomes of behavior tests（in-volving 45 rats）including Barnes maze test,motor coordination test and fear conditioning test,were evaluated 30 days after the HI brain injury.Results Intranasal AMA significantly increased the right-to-left hemispheric weight ratio,lowered the concen-trations of IL-1βand IL-6 in the right hippocampus of rats and promoted the behavior functions 15 min after ligation（P〈0.05） . Conclusion Intranasal AMA can provide neuroprotection partially by reducing the hippocampal inflammation in the neonatal rats with HI brain injury.