重型颅脑损伤合并缺血缺氧后氨基酸谱改变  

Alterations of amino acid zymogram after severe head injury with cerebral ischemic and hypoxia

作　　者：章翔[1] 费舟[1] 吴景文[1] 付洛安[1] 李侠[1] 梁景文[1] 

机构地区：[1]第四军医大学西京医院神经外科,陕西西安710032

出　　处：《中国危重病急救医学》2002年第11期643-645,共3页Chinese Critical Care Medicine

基　　金：国家自然科学基金资助项目 (No.3 9870 673 )

摘　　要：目的 :研究重型颅脑损伤 (SHI)合并缺血、缺氧时脑组织谷氨酸 (Glu)及环核苷酸代谢的改变及临床意义。方法 :在 SD大鼠弥漫性脑损伤模型基础上 ,制成 SHI合并低血压及脑缺血模型。通过氨基酸分析仪与放射免疫法测定伤后不同时间脑组织 Glu、c AMP和 c GMP含量。结果 :SHI后 10分钟 ,Glu明显增加〔(19.0±0 .9)μmol/ g(P<0 .0 1)〕,随后逐渐下降 ,并于 2 4小时达最低点〔 (6 .5± 1.0 )μmol/ g〕,72小时组出现回升趋势 ,但仍维持低水平 ;SHI后 2 4小时 c AMP下降至 (5 .7± 1.9) nm ol/ g(P <0 .0 5 ) ,c GMP则升高到 (1.1±0 .3) nm ol/ g(P<0 .0 1) ,c AMP/ c GMP比值下降到 (5 .0± 1.0 ,P<0 .0 5 ) ;SHI合并缺血、缺氧后 ,上述指标变化更加明显。结论 :在 SHI合并缺血、缺氧后 ,脑组织 Glu、c AMP和 c GMP含量发生显著变化 ,上述氨基酸谱的改变所引起的神经细胞兴奋毒性和代谢性应激反应是加重继发性脑损害的关键因素。Objective:To study the changes and clinical significance of glutamate(Glu) content and cyclic nucleotide levels in rat brain after severe head injury(SHI) combined with cerebral ischemic and hypoxia. Methods: On the bases of the SD rat diffuse brain injury model,the SHI animal model combined with hypotension and hypoxia were established.The changes of Glu content and cyclic nucleotide levels in rats brain were detected by immunoradioassay or microdetermination at different time after brain injury.Results:The Glu content increased distinctively after SHI,which was (19 0±0 9) μmol/g at 10 minutes after SHI( P <0 01),and then declined and reached its lowest level to (6 5±1 0) μmol/g at 24 hours after SHI,and then improved and remained at a lower level after 72 hours of injury.The levels of cAMP and the ratio of cAMP to cGMP were(5 7±1 9) nmol/g and (5 0±1 0) respectively(all P <0 05) at 24 hours after SHI,whereas cGMP level 〔(1 1±0 3) nmol/g〕 was increased( P <0 01).All these parameters change more dramatically after SHI combined with cerebral ischemic and hypoxia.Conclusions:Glu content,cAMP and cGMP levels changed significantly in rat brain after SHI combined with cerebral ischemic and hypoxia,which induce excitotoxicity and metabolic stress and may play important roles in deteriorating the brain damages.These changes should be considered adequately in clinical treatment of SHI.

关 键 词：脑缺血 谷氨酸 环核苷酸 脑缺氧 SHI 重型颅脑损伤 

分 类 号：R651.15[医药卫生—外科学] R743.31[医药卫生—临床医学]