Pluta R, Salínska E, Puka M, Stafiej A, Lazarewicz J W
Department of Neuropathology, Polish Academy of Sciences, Warsaw.
Resuscitation. 1988 Jul;16(3):193-210. doi: 10.1016/0300-9572(88)90046-9.
The effect of cerebral ischemia on extracellular amino acids and calcium content and on the permeability of the blood-brain barrier was studied by in vivo dialysis of rabbit hippocampus. This was combined with physiological and neurophysiological measurements. It was found that immediately after 15-min ischemia extracellular concentrations of glutamate, aspartate and taurine increased 3-, 2- and 6-fold, respectively, whereas a maximal, 7-fold increase of phosphoethanolamine and persistent elevation of glutamate were observed 45 min after ischemia. Extracellular calcium concentration, monitored with 45Ca2+, increased by 10% during the initial phase of ischemia, and decreased to approx. 74% of the basal level 10 min after ischemia. Recovery of extracellular calcium content was not attained until 45 min of recirculation, at which time the first signs of return of bioelectric activity were noted. Increased permeability of the blood-brain barrier to fluoresceine developed immediately after ischemia and persisted up to 2 h of recirculation. The obtained results are discussed in reference to the noted simultaneity of changes in extracellular excitatory amino acids and calcium concentrations and of brain bioelectric activity during and after ischemia. Causal relations between these effects are suggested.
通过对兔海马体进行体内透析，研究了脑缺血对细胞外氨基酸、钙含量以及血脑屏障通透性的影响。该研究结合了生理学和神经生理学测量。结果发现，缺血15分钟后，细胞外谷氨酸、天冬氨酸和牛磺酸的浓度分别增加了3倍、2倍和6倍，而缺血45分钟后，磷酸乙醇胺出现最大幅度的7倍增加，谷氨酸持续升高。用45Ca2+监测的细胞外钙浓度在缺血初始阶段增加了10%，缺血10分钟后降至基础水平的约74%。直到再灌注45分钟时细胞外钙含量才恢复，此时注意到生物电活动恢复的最初迹象。缺血后血脑屏障对荧光素的通透性立即增加，并持续到再灌注2小时。结合缺血期间和缺血后细胞外兴奋性氨基酸和钙浓度变化与脑生物电活动变化的同时性，对所得结果进行了讨论。提出了这些效应之间的因果关系。
