【作者】 刘宁宁；

【导师】 孙立忠；

【作者基本信息】 中国协和医科大学 ， 心血管外科， 2006， 博士

【摘要】 目的：建立猪脊髓微透析的动物模型，观察猪脊髓神经细胞间液中能量代谢相关物质和各种氨基酸的变化，探讨脊髓缺血和再灌注损伤的分子机制。 方法：本实验于2003年10月至2004年5月在阜外心血管病医院实验外科完成。6只成年中国小型香猪，首先在腰2段脊髓中植入微透析针，经左侧第4肋间开胸，游离降主动脉和左奇静脉。常温阻断主动脉和左奇静脉60分钟，开放再灌注90分钟。术后即刻取腰2段脊髓行HE染色，观察动物脊髓神经元细胞的损伤程度，计算活力指数。分别于阻断前、阻断30分钟、阻断60分钟、开放30分钟、开放60分钟和开放90分钟收集微透析样本。微透析样本分别检测能量代谢相关物质：葡萄糖、丙酮酸、乳酸和甘油；氨基酸：天门冬氨酸、谷氨酸、甘氨酸、γ-氨基丁酸和牛磺酸。观察不同时间点不同物质的变化趋势。方差分析和非参数检验完成统计分析。 结果：葡萄糖和丙酮酸的含量在主动脉阻断后降低，再灌注开始时达到最低点，此后含量逐渐升高，再灌注90分钟时未恢复。乳酸的含量在阻断后即出现明显升高，后无下降趋势。乳酸／丙酮酸比值在再灌注开始时达到高峰。脊髓神经细胞间液中的天门冬氨酸、甘氨酸和γ-氨基丁酸在主动脉阻断后和再灌注后期出现双峰升高。谷氨酸和牛磺酸在再灌注开始时升高。病理学检查：脊髓内神经元细胞明显损伤。 结论：猪脊髓缺血微透析的动物模型可以应用于损伤机制和保护效果评价的研究。兴奋性氨基酸在脊髓的缺血损伤中占有重要的地位。再灌注90分钟时谷氨酸、天门冬氨酸升高，可能与脊髓的再灌注损伤有关。更多还原

【Abstract】 Part oneMicrodialysis study of the spinal cord during thoracic aort-ic cross-clamping in a porcine modelObjective: Utilize microdialysis to investigate the concentration of amino acid and the changes in energy-related metabolites in spinal cord ischemia. Discuss the mechanism of injury of spinal cord during the ischemia and reperfusion periods.Methods: The experiments were performed in the department of experimental surgery of Fuwai Hospital from October 2003 to May 2004. Six swine were studied. Microdialysis probe was inserted into the lumbar 2 spinal cord to monitor extracellular glucose, lactate, pyruvate, glycerin, glutamate, asparagine, glycin, GABA and taurine during ischemia and reperfusion periods. A left side thoracotomy was performed in the fourth interspace. The descending thoracic aorta as well as the azygos vein was dissected, and the aorta was prepared for cross clamping just distal to the left subclavian artery. After 60 minutes spinal cord ischemia, the clamp was removed. After 90 min reperfusion pathological changes of lumbar segmental (L2) spinal cord were observed with the HE staining.Result: Glucose and pyruvate concentration decreased significantly with the lowest level observed following 60 min of aortic cross clamping. Lactate level increased significantly after aortic clamping. Also the increase of the lactate-pyruvate ratio was observed during aortic cross clamping. There was a significant increase in concentration of Asp, Gly, and GABA after aorta clamping and reperfusion. There was also a significant increase in Glu and Tau after 90 minutes reperfusion. The number of neurons of spinal cord was fewer and degenerative atrophy of spinal cord could be seen by histological examination.Conclusion: Microdialysis reflects the ischemic state of the spinal cord, and is well suited to study each phenomenon. Amino acid plays different roles in the spinal cord ischemia. Glu and Asp may play a key role in the reperfusion injury of spinal cord.更多还原