Mechanism of ischemic tolerance phenomenon in hippocampal CAI sector of the gerbil

点击翻译按钮获取中文摘要

Following brief cerebral ischemia, tolerance to subsequent ischemia is induced in the hippocampal neurons. The aim of this study was to investigate the relationship between ischemic tolerance phenomenon and protein synthesis. First, recovery of protein synthesis was studied autoradiographically in gerbils with induced tolerance. To observe the effect of tolerance acquisition, double forebrain ischemia, 2-min ischemia followed by 5 min-ischemia, was induced 2 days later. In this group, recovery of protein synthesis in the CAI sector was rapid. At 1 day of recirculation, protein synthesis returned near normal. On the other hand, protein synthesis in the 5-min ischemia group was severely suppressed and never returned to the normal level. The present study revealed an early recovery of protein synthesis in the hippocampal neurons in the gerbil with induced tolerance. Secondly, possible differences in electrophoresis pattern of the brain protein between tolerance-induce animals and animals injected with protein synthesis inhibitor. There was no differences in the pattern of the protein between these two groups. Thirdly, we investigated whether multiple sublethal ishemia can enhance the ability of tolerance induction or prolong the period of tolerance. At 1 month after the multiple exposure to sublethal 2-min ischemia, animals did not acquire ischemic tolerance to 4-min lethal ischemia. To clarify the mechanism of ischemic tolerance, further studies are needed.