Tanaka H, Katayama Y, Kawamata T, Tsubokawa T
Department of Neurological Surgery, Nihon University School of Medicine, Tokyo, Japan.
Acta Neurochir Suppl (Wien). 1994;60:524-7. doi: 10.1007/978-3-7091-9334-1_144.
The EAA release from contused brain tissue and its effect on the extracellular EAA levels in brain areas surrounding the contusion were investigated with microdialysis technique in the rat. A significant increase in extracellular EAA levels was observed in the contused brain tissue. The EAA increase was significantly greater in the contused brain tissue than in the isolated but non-contused brain tissue. It was further demonstrated that EAAs were released from non-contused brain areas 1-2 mm distant from contused brain tissue. No such EAA release from surrounding brain areas was demonstrated when the cavity was filled with isolated but non-contused brain tissue. The increase in EAAs was attenuated by KYN administered through microdialysis, suggesting that the EAA release from the surrounding brain areas appears to be a consequence that is secondary to the EAA release from the contused brain tissue. Such a diffusion-reaction process is probably mediated by the neurotransmitter actions of EAAs. The results of the present study are of clinical importance, since surgical removal of contused brain tissue and administration of EAA antagonists may serve to protect the surrounding brain areas from EAA neurotoxicity.
采用微透析技术在大鼠中研究了挫伤脑组织中兴奋性氨基酸（EAA）的释放及其对挫伤周围脑区细胞外EAA水平的影响。在挫伤脑组织中观察到细胞外EAA水平显著升高。挫伤脑组织中EAA的升高明显大于分离但未挫伤的脑组织。进一步证明，EAA从距挫伤脑组织1-2毫米的未挫伤脑区释放。当腔中填充分离但未挫伤的脑组织时，未显示周围脑区有这种EAA释放。通过微透析给予犬尿氨酸可减弱EAA的升高，这表明周围脑区的EAA释放似乎是挫伤脑组织EAA释放的继发结果。这种扩散-反应过程可能由EAA的神经递质作用介导。本研究结果具有临床意义，因为手术切除挫伤脑组织和给予EAA拮抗剂可能有助于保护周围脑区免受EAA神经毒性的影响。
