In Vivo Microdialysis Study of Excitatory and Inhibitory Amino Acid Levels in the Hippocampus Following Penicillin-Induced Seizures in Mature Rats

以活體微透析法研究由配尼西林引發的癲癇老鼠在海馬迴內興奮性與抑制性氨基酸濃度：研究小兒癲癇的動物模式

沈淵瑤(Ein-Yiao Shen) ； 賴宇俊(Yu-Jan Lai)

《Acta Paediatrica Taiwanica》 43卷6期 (2002/12) Pp. 313-318

https://doi.org/10.7097/APT.200212.0313

摘要

爲研究兒童癲癇的致病機轉，吾人進行一項試驗以配尼西林注入海馬迴引發癲癇發作的動物模型。先以微透析裝置植入Spraque-Dawley大白鼠的海馬迴，再以不同濃度注入海馬迴引發痙攣，然後藉助微透析法分析在深入分析在活體內局部腦組織腦脊髓液的興奮性與抑制性濃度變化。吾人分別以334單位，668單位及1336單位配尼西林注入一側海馬迴，結果發現以668及1336單位會致命麥氨酸明顯上昇，而在40分鍾後恢複正常。天門冬氨酸在同時間上昇及下降，但無統計上意義。以1336單位配尼西林注射可致使抑制性氨基酸包括γ-氨基丁酸、甘氨酸及氨基乙磺酸明顯上昇但緩慢下降，同時記錄的腦波也明顯的癲癇波。此研究發現足量的配尼西林可導致局部組織腦脊髓液的興奮性氨基酸上昇，腦波出現明顯半音波，抵制性氨基酸同步上但緩慢下降。吾人認爲此動物癲癇模型的設立，可提供未來對癲癇發作的機轉研究與療效觀察，一項很好的實驗方式。

關鍵字

微透析術 ； 配尼西林 ； 癲癇 ； 興奮性氨基酸 ； 抑制性氨基酸

並列摘要

To investigate the basic mechanism of epileptogenecity in children, we undertook a study of application of penicillin (PC) to the brain of an animal model. Different doses of PC were injected into the hippocampus of Spraque-Dawley ruts subjected to microdialysis to observe in vivo changes of excitatory amino acid (EAA) and inhibitory amino acid (IAA) levels during seizure. All of the EAA and IAA levels increased in the interstitial cerebrospinal fluid (CSF) after focal application of PC. We found that 668 and 1336 units of PC were enough to increase glutamate levels significantly. These levels consistently declined to nearly normal within 40 minutes after PC injection. The aspartate level increased soon after PC injection without statistical significance and then declined almost to baseline level. The IAA, r-aminobulyric acid (GABA), glycine, and taurine levels increased significantly after injection of 1336 u of PC. EEG recording of spike discharges was also well defined after the injection of 1336 u of PC. Our study suggests that an adequate PC dose to the hippocampus will enhance the release of EAA and IAA in the brain as well as epileptogenecity on EEG activity. Using in vivo microdialysis, EAA and IAA can be studied during an induced epileptic process. Elevation of EAA levels soon after focal chemical stimulation of the brain provides a good model for study of epileptogenecity. A delay in the decline of IAA levels may suggest an important phenomenon in seizure suppression and is also worthy of further study.

並列關鍵字

microdialysis ； penicillin ； epilepsy ； excitatory amino acids ； inhibitory amino acids