第八章肝胆疾病的生物化学诊断课件_1

第八章 肝胆疾病的 生物化学诊断 临床生化教研室 罗洁讲师 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 主要内容 一、解剖结构基础与生物化学功能 二、肝脏的生物转化作用 三、胆红素与胆汁酸代谢及其异常 四、肝病的生物化学代谢紊乱 五、肝胆疾病的肝功能实验室检查 六、肝功能检验项目选择原则与评价 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 第一节 解剖结构基础与生物化学功能 一、解剖结构特点一、解剖结构特点 二、肝脏的生物化学功能二、肝脏的生物化学功能 三、肝细胞损伤时的代谢变化三、肝细胞损伤时的代谢变化 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 1. 血管丰富门静脉和肝动脉双重血供，且有肝 静脉和胆道系统排泄 2. 微细结构 3.化学组成-含众多酶系 物质的转运基础-大量微绒毛 物质交换的基础-较高通透性 能量保证的基础-线粒体丰富 物质代谢的基础-亚细胞结构丰富 故肝脏有“物质代谢中枢”之称！ 一、解剖结构特点 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 二、肝脏的生物化学功能 人肝细胞生长因子结构 1. 代谢功能（参与糖、蛋白质 、脂类和维生素等物质代谢） 2. 生物转化作用 3. 分泌和排泄功能 4. 造血功能 5. 激素的灭活 6. 肝脏再生功能 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 三、肝细胞损伤时的代谢变化 1.急性肝损害时，血浆蛋白质浓度变化不大。 慢性肝病时: l血浆清蛋白降低，-球蛋白升高，出现清蛋 白与球蛋白（A/G）的比值降低，甚至倒置。 l血浆尿素水平呈低值。 l血氨增高。 l支链氨基酸和芳香族氨基酸的比值下降。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2. 糖代谢变化 l磷酸戊糖途径和糖酵解途径相对增强，血中丙酮 酸含量可显著上升。 l严重肝病时糖有氧氧化及三羧酸循环运转失常。 l血糖浓度难以维持正常水平。 l糖耐糖曲线异常，可呈低平型、高峰型、高坡型 等异常曲线 。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 3. 脂类代谢变化 l脂类消化吸收不良。 l肝内脂肪氧化分解降低或脂肪合成增多或磷脂合成障碍 ，不能有效合成脂蛋白输出，脂肪在肝细胞内沉积而形 成脂肪肝。 l糖代谢异常，脂肪动员增加，导致酮血症 。 l血浆胆固醇酯/胆固醇的比值下降。 l血浆脂蛋白电泳谱异常，出现低密度脂蛋白(LDL)积累 。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 一、生物转化的概念一、生物转化的概念 第二节 肝脏的生物转化作用 二、生物转化的反应类型二、生物转化的反应类型 三、生物转化的特点三、生物转化的特点 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 1. 生物转化的定义 一些非营养物质在体内的代谢转变过程称为 生物转化 2. 生物转化的对象 非营养物质 内源性：如激素、胺类等 外源性：如药物、毒物等 一、生物转化的概念 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 二、生物转化的反应类型 1. 第一相反应：氧化反应 还原反应 水解反应 2. 第二相反应：结合反应 * 有些物质经过第一相反应即可顺利排出体外 。 * 有些物质即使经过第一相反应后，极性改变 仍不大，必须与某些极性更强的物质结合, 即第二相反应，才最终排出。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 1. 微粒体依赖P450加单氧酶系 l部位：微粒体内(滑面内质网)。 l组成：Cyt P450,NADPH+H+，NADPH-细胞色素P450还原 酶。 l催化的基本反应。 RH+O2+NADPH+H+ ROH+NADP+H2O l基本特点: 能直接激活氧分子，其中一个氧原子加 入底物分子中，另一氧原子被还原为水，故又称为 混合功能氧化酶 (如图, 示例) Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 返回节 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 多环芳烃的生 物转化过程 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2. 线粒体单胺氧化酶系 u存在部位：线粒体内 u催化的反应: 催化胺类氧化脱氨基生成相应 的醛 RCH2NH2+H2O2RCHO+NH3+H2O Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 3. 醇脱氢酶及醛脱氢酶系 存在部位：胞液 催化的反应 醇脱氢酶(ADH)催化醇类氧化成酸 醛脱氢酶(ALDH)催化醛类生成酸 还原反应还原反应: : 此类酶的活性一般不高此类酶的活性一般不高 存在部位：微粒体 催化反应: 硝基还原酶类 和偶氮还原酶类 在无氧条件下，生成 胺类。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 水解反应水解反应 分布广泛 种类繁多-肝细胞中有各种水解酶。 结合反应结合反应第二相反应第二相反应 存在部位：微粒体、胞液和线粒体内 结合对象：凡含有羟基、羧基或氨基的药物、 毒物或激素均可发生结合反应。 结合剂：葡萄糖醛酸、硫酸、谷胱甘肽、甘氨 酸、乙酰基、甲基等物质或基团。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 1. 葡萄糖醛酸结合反应最多见的结合反应 l葡萄糖醛酸基的直接供体-尿苷二磷酸葡萄糖醛酸 (UDPGA) l催化酶-葡萄糖醛酸基转移酶 (UGT), 示例: 苯葡糖醛酸苷 + UDP 苯酚 + UDPGA UDPG脱氢酶 2NAD+ 2NADH+ 2H+ UDPG UDPGA Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2. 硫酸结合反应 p硫酸供体-3磷酸腺苷-5磷酸硫酸( PAPS) p催化酶-硫酸转移酶 示例: 雌酮 雌酮硫酸酯 PAP PAPS HO3SO Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 3. 酰基化反应 异烟肼 乙酰辅酶A 乙酰异烟肼 辅酶A +CH3COCoA +HS-CoA Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 4. 谷胱甘肽结合反应 环氧萘 谷胱甘肽 S-二氢萘醇谷胱甘肽 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 5. 甲基化反应 甲基的供体：S - 腺苷甲硫氨酸(SAM) + S -腺苷甲硫氨酸 甲基转移酶 N CONH2 CH3 + + S -腺苷同型半胱氨酸 尼克酰胺 N-甲基尼克酰胺 N CONH2 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 三、生物转化的特点 连续性 多样性 解毒与致毒双重性 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 第三节 胆红素与胆汁酸代谢及其异常 一、胆红素代谢与黄疸一、胆红素代谢与黄疸 二、胆汁酸代谢及其异常二、胆汁酸代谢及其异常 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 1.胆红素来源 体内的铁卟啉化合物血红蛋白、肌红蛋白、 细胞色素、过氧化氢酶及过氧化物酶（如图）。 （一）胆红素的生成与转运 一、胆红素代谢与黄疸 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 胆红素来源 1）衰老的RBC破坏、降解 2）无效红细胞生成 3）非血红蛋白的血红素蛋白质 （细胞色素、过氧化物酶、 肌红蛋白等）分解 分流胆红素 （20%） 主流胆红素 （80%） Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.胆红素的生成过程 衰老的RBC Hb 胆红素a CO和铁 胆绿素 氨基酸 血红素 珠蛋白 血红素加单氧酶 胆绿素还原酶 O2、NADPH 肝、脾、骨髓 （微粒体、胞液） 网状内皮系统 胆红素的性质：亲脂疏水，对大脑具有毒性作用 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 胆红素的生成过程 + + + + Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. C10 胆红素空间结构示意 图 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 3胆红素转运 运输形式 竞争结合剂 意 义 胆红素1-球蛋白（少部分） -如磺胺药，水杨酸，胆汁酸等 胆红素清蛋白复合体（主要） 增加胆红素在血浆中的溶解度，便于运输 限制胆红素自由通过生物膜产生毒性作用 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 4. 胆红素在肝细胞内转变 1）摄取-胆红素可以自由双向通透肝血窦肝细胞膜表面进 入肝细胞。 肝内运输 胆红素摄取的 有效性取决于 肝细胞膜上特异的载体蛋白 肝细胞内Y蛋白和Z蛋白两种受体蛋白 以“胆红素Y蛋白”(胆红素Z蛋白) 形式送至内质网。 这是一个耗能的可逆的过程。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2）转化 l部位：滑面内网质 l反应：结合反应（主要结合物为UDPGA） l酶： 葡萄糖醛酸基转移酶。 l产物：主要为双葡萄糖醛酸胆红素，另有少量单葡 萄糖醛酸胆红素、硫酸胆红素，统称为结合胆红素 。 l目的：既有利于胆红素随胆汁排泄，又限制其通过 生物膜而起到解毒作用。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 胆红素 + UDP -葡糖醛酸 胆红素葡糖醛酸一酯 + UDP （10 % 20%） UDP-葡糖醛酸基转移酶 胆红素葡糖醛酸一酯 + UDP -葡糖醛酸 胆红素葡糖醛酸二酯 + UDP （80 % 90%） 葡糖醛酸胆红素的生成 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. C10 胆红素葡糖醛酸二酯的结构 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 3）排泄 u结合胆红素通过毛细胆管膜上的主动转运载 体，从肝细胞毛细胆管排泄入胆汁中，再随 胆汁排入肠道。 u转运形式：逆浓度梯度的能量依赖的主动转 运过程。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 5. 胆红素在肠管中的变化及其肠肝循环 胆素原：中胆素原，粪胆素原，d -尿胆素原 胆 素：i -尿胆素，粪胆素， d -尿胆素 胆素 胆素原 游离胆红素 结合胆红素 -葡萄糖醛酸苷酶 还原 氧化 葡萄糖醛酸 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 胆红素与胆酸的生成反应 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 胆素原肠肝循环的概念 肠道中有少量的胆素原可被肠粘膜细 胞重吸收，经门静脉入肝，其中大部分再随 胆汁排入肠道，形成胆素原的肠肝循环。 胆素原的肠肝循环 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. （1020%） 25% 胆素原肠肝循环的过程 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 胆红素代谢通路 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. （二）胆红素代谢紊乱与黄疸 1. 黄疸的概念： 凡能引起胆红素生成过多、或肝细胞对胆红素的摄取、结合 和排泄过程发生障碍等因素均可使血中胆红素增高，而出现高胆 红素血症。 胆红素是金黄色色素，当血清中浓度高时，则可扩散入组 织，组织被染黄，称为黄疸。 l隐性黄疸：1mg/dl1mg/dl1mg/dl 结合胆红素 00.8 mg/dl 游离胆红素1 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 二、胆汁酸代谢及其异常 1.胆汁酸的类型 l按结构分 l按来源分 游离胆汁酸-CA,CDCA,DCA,LCA 结合胆汁酸-与甘氨酸或牛磺酸结合 初级胆汁酸 次级胆汁酸 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 例：胆酸 例：鹅脱氧胆酸 游离胆汁酸 H COOH HO OH OH 3 12 7 24 COOH HHO 37 12 OH Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 例：牛磺胆酸 例：甘氨胆酸 结合胆汁酸 CONHCH2CH2SO3H CONHCH2COOH H HO 3 12 7 H OH 3 12 7 OH OH HO Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 概念：是肝细胞以胆固醇为原料直接合成的胆汁酸。 类型： 胆酸(CA)、鹅脱氧胆酸(CDCA)及相应结合型胆汁酸。 部位：肝细胞的胞液和微粒体中 原料：胆固醇 初级胆汁酸 概念：在肠道细菌作用下初级胆汁酸 7-羟基脱 氧后生成的胆汁酸 类型：脱氧胆酸(DCA) 、石胆酸(LCA)及相应结合型 胆汁酸 部位：小肠下段和大肠 次级胆汁酸 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2. 胆汁酸代谢 1) 初级胆汁酸形成 还原、侧链修饰 胆酸（3，7，12 三羟胆固烷酸，CA） 脱氧胆酸 （3，7二羟胆固烷酸，CDCA） 7，12二羟 4胆固烯3酮 7羟4胆固烯3酮 7羟胆固醇 胆固醇 12羟化酶 氧化异构 7羟化酶 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2) 次级胆汁酸形成 初级胆汁酸 次级胆汁酸 7-羟基酶 胆酸 脱氧胆酸 H COOH OH O H O H 3 12 7 H COOH OH O H 3 12 7 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 初级胆汁酸 次级胆汁酸 鹅脱氧胆酸 石胆酸 7-羟基酶 H COOH OH O H 3 12 7 H COOH OH 3 12 7 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 概念： 胆汁酸随胆汁排入肠腔后，通过重吸收经门静脉 又回到肝，在肝内转变为结合型胆汁酸，经胆道再次 排入肠腔的过程。 意义： 将有限的胆汁酸反复利用以满足人体对胆汁酸的 生理需要，促进脂类的消化吸收。 3) 胆汁酸肠肝循环 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 胆汁酸肠肝循环的过程 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 3. 胆汁酸代谢异常 胆汁酸代谢遗传性缺陷 肝胆疾病时的代谢异常 肠道疾病时的代谢异常 高脂蛋白血症时的代谢异常 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 1.肝胆疾病患者，血清胆汁酸水平无区别升高。 2.对肝功能评估具有较高的诊断灵敏度，尤其是餐后 小时检测。 3.TBA检测可用来区别高胆红素血症和胆汁淤积。 4.CA/CDCA比值可作为胆道梗阻性病变和肝实质细 胞性病变的鉴别指标。比值，见于胆道梗阻性 病变；反之，见于肝实质细胞性病变。 肝胆疾病与肝胆疾病与TBATBA Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 在小肠疾病时，可引起胆汁酸代谢异常，如回肠切 除、炎症或分流（如造漏）等，因胆汁酸的肠肝循环受 阻，胆汁酸回到肝脏的量减少，血清胆汁酸水平降低； 同时，由于胆汁酸返回肝脏减少，反馈抑制减弱，致肝 脏胆汁酸的合成加速，血清胆固醇浓度减低。可见血清 胆汁酸水平降低是回肠功能紊乱的一个反映。 肠道疾病与肠道疾病与TBATBA Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 胆汁酸的生成是内源性胆固醇的主要代谢去路，而 胆汁酸的合成又依赖自身的负反馈调控。 肝细胞依靠胆汁酸的乳化及其形成的混合微团作用 而随胆汁分泌排泄胆固醇，因此胆汁酸的合成和分 泌必然影响胆固醇的排泄。 胆汁酸协助食物胆固醇的吸收，而吸收的胆固醇可 直接调控肠壁细胞及肝细胞内胆固醇的合成。 因此，高脂蛋白血症时的代谢紊乱必然涉及胆 汁酸的代谢异常。 高脂蛋白血症与胆汁酸代谢高脂蛋白血症与胆汁酸代谢 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 第四节 肝病的生物化学代谢紊乱 一、肝硬化的临床生物化学一、肝硬化的临床生物化学 二、乙醇性肝脏疾病的生物化学二、乙醇性肝脏疾病的生物化学 四、胆石症的临床生物化学四、胆石症的临床生物化学 三、肝昏迷的临床生物化学三、肝昏迷的临床生物化学 五、肝癌的临床生物化学五、肝癌的临床生物化学 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 1.肝硬化的生物化学机制 l缺氧和炎症刺激，导致胶原纤维合成增强。以I型及 型为主。 l机体免疫机能不足，肝细胞反