Multiple analysis of brain metabolism in ischemia

建立了灌注法调节大鼠前脑缺血的实验模型。准备工作主要包括闭塞双侧耳外动脉、翼腭动脉和基底动脉，然后用泵将股动脉血液经双侧颈总动脉灌注到脑内。研究了该模型的脑电图结果和14c -碘安替比林放射自显像定性脑血流，提示该模型在脑缺血基础研究中的可能作用。建立大鼠七支血管闭塞模型（双侧翼腭、颈外动脉、颈总动脉和基底动脉闭塞），产生完全的前脑缺血，无全身性低血压，并用于后续研究。30min缺血后5min再灌注，CBF放射自显像证实再灌注模式受损主要发生在基底节区，而甘露醇预处理动物的再循环模式均匀且充血。这表明甘露醇可以预防暂时性缺血后的再灌注损伤。采用18FDG和14c -亮氨酸多重标记放射自显像同时研究缺血后再灌注期葡萄糖和氨基酸代谢。在再灌注受损的脑深部，观察到葡萄糖和氨基酸代谢的分离。这些结果将为我们了解代谢与脑缺血再灌注损伤之间的病理生理学相关性提供重要线索。

An experimental model of rat forebrain ischemia regulated with perfusion method was created. The preparation mainly consists of the occlusion of bilateral externel earotid, pterygopalatine arteries and basilar artery, then the brain is perfused by the femoral artery blood using a pump through bilateral common carotid arteries. EEG findings and qualitative CBF by 14C-iodoantipyrine autoradiography of this model were studied, which indicate the possible usefulness of this model in the basic investigation of cerebral ischemia.A seven vessel occlusion model in the rat (occlusion of bilateral pterygopalatine, external carotid, common carotid arteries, and basilar artery) that produced complete forebrain ischemia without systemic hypotension was developted and used for following studies.After 5min reperfusion following 30min ischemia, impaired reperfusion pattern was verified mainly in basal ganglia by CBF autoradiography, while, the recirculation pattern in mannitol pretreated animals was homogeneous and hyperemic. This indicates that mannitol prevented impairment of reperfusion after temporary ischemia.Glucose and amino acid metabolism in reperfusion phase after ischemia was studied simultaneously by 18FDG and 14C-leucine multiple labeled autoradiography. The dissociation between blucose and amino acid metabolism was observed in deep part of the brain where the reperfusion tended to be impaired.These results will provide us an important clue for undestanding pathophisiological corellation between metabolism and postischemic damage of the brain in reperfusion.