Lin Sheng, Zhou Guangli, Shao Wei, Fu Zhijian
MD, Department of Anesthesiology, Yantaishan Hospital, China. Conception and design of the study, manuscript writing, final approved.
MD, Department of Pain, Provincial Hospital, Shandong University, China. Analysis of data, final approved.
Acta Cir Bras. 2017 Jun;32(6):459-466. doi: 10.1590/s0102-865020170060000006.
: To investigate the effects of dexmedetomidine (DEX) on amino acid contents and the cerebral ultrastructure of rats with cerebral ischemia-reperfusion injury (I/R).
: Thirty-six, male, Wistar rats were randomly divided into three groups: the sham operation group (group C), the ischemia-reperfusion group (group I/R), and the DEX group (group D). The middle cerebral artery occlusion model was prepared by the modified Longa method. The time of ischemia was 180 min, and 120 min after reperfusion, the amount of glutamate (Glu), and γ-aminobutyric acid (GABA) in the brain were measured, and the ultrastructure-level changes in the cerebral cortex were examined using electron microscopy.
: Compared to group C, Glu contents in group D, and I/R significantly increased. Compared to group I/R, Glu contents in group D significantly decreased. Compared to group C, GABA contents in group D, and I/R significantly increased, and those in group D significantly increased, as compared to group I/R. The cerebral ultrastructure was normal in group C. Vacuolar degeneration in the plastiosome and nervous processes, was more critical than in group D. Vascular endothelial cells (VEC) were damaged. On the contrary, these changes in group D significantly improved.
: Dexmedetomidine is capable of decreasing glutamergic content, and increasing GABAergic content, in order to decrease the injury of the cerebral ultrastructure, following cerebral ischemia-reperfusion injury.
探讨右美托咪定（DEX）对脑缺血再灌注损伤（I/R）大鼠氨基酸含量及脑超微结构的影响。
将36只雄性Wistar大鼠随机分为三组：假手术组（C组）、缺血再灌注组（I/R组）和DEX组（D组）。采用改良的Longa法制备大脑中动脉闭塞模型。缺血时间为180分钟，再灌注120分钟后，测定脑中谷氨酸（Glu）和γ-氨基丁酸（GABA）的含量，并用电子显微镜观察大脑皮质超微结构水平的变化。
与C组相比，D组和I/R组的Glu含量显著增加。与I/R组相比，D组的Glu含量显著降低。与C组相比，D组和I/R组的GABA含量显著增加，且D组与I/R组相比GABA含量显著增加。C组脑超微结构正常。I/R组线粒体和神经突起的空泡变性比D组更严重，血管内皮细胞（VEC）受损。相反，D组的这些变化明显改善。
右美托咪定能够降低谷氨酸能含量，增加γ-氨基丁酸能含量，以减轻脑缺血再灌注损伤后脑超微结构的损伤。
