1、氨在肝性脑病发病机制中的作用氨在肝性脑病发病机制中的作用知识回顾知识回顾l概念概念l临床表现临床表现l氨中毒学说氨中毒学说l一、目的一、目的l二、药品器材动物二、药品器材动物l三、方法步骤三、方法步骤l四、结果四、结果l五、讨论分析五、讨论分析l六、结论六、结论操作步骤操作步骤l 固定、固定、局麻局麻l 上腹部上腹部正中切口正中切口,开腹,开腹l 剪镰状韧带剪镰状韧带l 辩明肝叶、辩明肝叶、肝叶结扎肝叶结扎l 12指肠指肠荷包缝合荷包缝合并插管并插管l 腹壁全层腹壁全层连续缝合连续缝合,关腹腔,关腹腔l 观察观察l 输液(输液(60滴滴/分)分)l 动物动物大抽搐大抽搐时,记录时间用量时,记录
2、时间用量l 动物死亡时,动物死亡时,记录时间用量记录时间用量局麻局麻镰状韧带镰状韧带肝脏各叶肝脏各叶结扎肝叶结扎肝叶荷包缝合荷包缝合十二指肠插管十二指肠插管腹壁全层连续缝合腹壁全层连续缝合大抽搐大抽搐,脚弓反张脚弓反张,肌肉强直肌肉强直l实验分组实验分组如下:如下:l甲组:肝叶结扎甲组:肝叶结扎+滴注氯化铵滴注氯化铵l乙组:肝叶不结扎乙组:肝叶不结扎+滴注氯化铵滴注氯化铵l丙组:肝叶结扎丙组:肝叶结扎+滴注氯化钠滴注氯化钠l丁组:肝叶结扎丁组:肝叶结扎+耳缘推注谷氨酸钠溶液耳缘推注谷氨酸钠溶液20ml/kg+滴注氯化铵滴注氯化铵结果结果 抽搐抽搐 死亡死亡 时间时间 用量(用量(ml/kg)
3、时间时间 用量(用量(ml/kg) 甲甲 12 25.6 24 46.6乙乙 22 35.7 35 40.7丙丙丁丁 16/18 29.4 /26.8 25 52.9 注意比较丙组与甲组;甲组与乙组;丁组与甲组注意比较丙组与甲组;甲组与乙组;丁组与甲组注意事项注意事项l剪镰状韧带时勿伤及膈肌和血管剪镰状韧带时勿伤及膈肌和血管l肝叶扎紧肝叶扎紧l1212指肠插管的方向指肠插管的方向l各组液体滴速尽量保持一致各组液体滴速尽量保持一致(60(60滴滴/ /分分) ) NH4+ NH3H+OH-LiverKrebs-HeneseleitureaBBBBrain1.Impairment of energ
4、y metabolism 2.Alteration of neurotransmittersfunction ImpairedPortosystemic shunting NH3 production (from small intestine)clearance (liver insufficiency/dysfunction)What reasons cause the blood ammonia elevated? ornithinecitrullinearginine arginase ureaKrebs-Heneseleit urea cycleThere would be prod
5、uced 1 urea molecule and use up 3 NH3 molecules every one circle.pH=7.4, 99% 1% NH37.45, NH3 H+OH- NH4+ NH3Easy to be absorbed, and pass through into BBBHave toxic effect on brain cellDifficulty to be absorbed,and go across into BBBHave no toxic effect on brain cellWhich is the toxic to brain cell? NH4+ NH3H+OH-GlutamineBBBBrain+MSG NH3Glutamine, a kind of biogenic amine, cant pass through BBB, only in peripheral blood, rather than cerebrospinal fluid.结论结论