【摘 要】 目的 探索脑缺血再灌注损伤后甘露醇干预的最佳时机。方法 对缺血再灌注即刻、30min、1h、1.5h甘露醇干预后小鼠海马CA1区细胞的病理形态学变化、存活细胞数和变性细胞率作出检测。结果 脑缺血再灌注即刻甘露醇干预组锥体细胞大多保持正常形态，细胞结构完好，细胞间质无水肿表现；存活细胞数为（22.00±1.1）个/100μm，与假手术组（23.00±0. 9）个/100μm无显著差别（P＞0.05）；变性细胞率（8.17%）较对照组（40.17%）明显减少（P＜0.05）；与假手术组（7.33%）无显著差别（P＞0.05）。再灌注30 min以上甘露醇再干预，神经元损伤不能改善。结论 脑缺血再灌注早期血压梯度建立后及时给予甘露醇建立反相的渗透压梯度，可以有效防止细胞水肿的形成，并能阻断由此引发的不可逆细胞损害。本研究发现恢复灌注30min以上再给予甘露醇基本无效。
【Abstract】Objective To investigate the optimal time of mannitol intervention in cerebral ischemia-reperfusion injury. Methods Morphological changes, viability and degradation of cells in the area of CA1 of hippocampus were studied at the time of 0 minutes, 30 minutes, 1 hour and 1.5 hours after reperfusion. Results In the experimental group in which mannitol intervention was administered immediately after reperfusion, most hippocampal pyramidal cells remained normal morphology with intact structures and no intercellular edema was observed . The amount of viable cells was 22.00±1.1 per 100μm and was not significantly different from that of the sham operation group (23.00±0.9). The incidence of cell degradation was 8.17%, which was significantly less than that of the control group (40.17%) with P<0.05. The difference of this index was not significant compared with that of the sham operation group(7.33%) with P>0.05. Mannitol intervention beginning over 30 minutes after reperfusion failed to alleviate neuron injury. Conclusion Inverted osmotic pressure gradient by means of prompt mannitol intervention can effectively prevent the formation of intracellular edema and avoid the consequent irreversible cellular injury after the establishment of blood pressure gradient at the early stage of cerebral ischemia-reperfusion. Mannitol intervention beginning over 30 minutes after reperfusion proves ineffective.
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