Zhao H, Asai S, Kohno T, Ishikawa K
Department of Pharmacology, Nihon University School of Medicine, Tokyo, Japan.
Neuroreport. 1998 Oct 5;9(14):3183-8. doi: 10.1097/00001756-199810050-00011.
We simultaneously measured extracellular glutamate ([Glu]e) elevation and local CBF using a real-time monitoring method and laser-Doppler flowmetry, respectively, in the rat striatum in a modified graded global ischemia model. Ischemic brain temperatures were kept at 32 degrees C, 37 degrees C and 39 degrees C. Three distinct types of intraischemic [Glu]e elevation, reflecting mild, moderate and massive glutamate release, were observed. Brain temperature plays an important role in determining CBF thresholds for each of the three types of [Glu]e elevation. CBF thresholds for [Glu]e elevations shifted to a lower level range as brain temperature was reduced. In mild or moderate ischemia, there is no exposure to sustained [Glu]e elevation, which is seen only in relatively severe ischemia characterized by biphasic [Glu]e elevation.
在改良的分级全脑缺血模型中，我们分别使用实时监测方法和激光多普勒血流仪，同时测量大鼠纹状体外周谷氨酸盐（[Glu]e）升高和局部脑血流量（CBF）。缺血性脑温保持在32摄氏度、37摄氏度和39摄氏度。观察到三种不同类型的缺血期[Glu]e升高，分别反映轻度、中度和大量谷氨酸释放。脑温在确定三种类型[Glu]e升高各自的CBF阈值方面发挥重要作用。随着脑温降低，[Glu]e升高的CBF阈值移至更低水平范围。在轻度或中度缺血中，不存在持续的[Glu]e升高，这种情况仅在以双相[Glu]e升高为特征的相对严重缺血中出现。
