脑缺血再灌注胃肠损伤老龄大鼠单胺类神经递质和自由基代谢的变化

目的 :从多巴胺 (DA)、去甲肾上腺素 (NE)、肾上腺素 (E)变化和自由基损伤方面揭示脑缺血再灌注胃肠损伤的机制。方法 :青年 ( 5月龄 )和老龄 ( 2 0月龄以上 )大鼠均分为模型组和正常对照组 ,观察大鼠全脑缺血 30min再灌注 60min后胃肠损伤的病理改变和超氧化物岐化酶 (SOD)的活性及丙二醛 (MDA)、DA、NE、E含量。结果 :青年和老龄模型组胃肠出现明显的病理改变。青年和老龄模型组交感 肾上腺系统兴奋性增强 ,其中老龄模型组较青年模型组大鼠严重。老龄对照组和青年模型组胃肠组织MDA/SOD比值高于青年对照组 ,老龄模型组胃组织MDA/SOD比值高于老龄对照组和青年模型组。结论 :大鼠脑缺血再灌注胃肠损伤与交感 肾上腺系统兴奋性增强和自由基损伤有关 ,由于增龄的变化使老龄大鼠脑缺血再灌注胃肠损伤时这些变化明显并具有一定特点。

Changes of monoamine nervous transmitter and free radical met abolism in aged rats with gastrointestinal injury after brain ischemia reper fusion

Objective: To study the mechanism of gastrointestinal injury after brain ischemia reperfusion in aged rats from the changes of dopamine(DA),noradrenalin(NE),epinephrine(E) and the injury of free radical.Methods: Young(5months) and aged (20 months or more) rats were divided into young model group (YMG),young control group(YCG),aged model group(AMG),aged control group(ACG).The following items were measured in rats with 60 minute reperfusion after 30 minute brain ischemia:the pathological change of gastrointestinal tract:the activities of super oxide dismutase(SOD),the contents of MDA,DA,NE,E.Results: The pathological change of gastrointestinal tract was found in the YMG and the AMG.The excitability of sympathetic adrenal system was enhanced in the YMG and the AMG,this change in the AMG was serious compared with that in the YMG.The gastrointestinal MDA/SOD ratio was larger in the ACG and the YMG than that in the YCG.The stomach MDA/SOD ratio was larger in the AMG than that in the ACG and the YMG.Conclusion: The gastrointestinal injury after brain ischemia reperfusion in aged rats was correlated with the change of the enhanced excitability of sympathetic adrenal system and free radical injury.With aging these pathological change were obvious and distinctive compared with that in the young rats.