2018-01-22 酒癮患者如果沒給thiamine 先打葡萄糖水, 會發生甚麼事情呢? ... 多數的病人都是因為酗酒而引起的，然而少數的病人可以因為營養缺乏等因素 ...急診小醫師https://dictionary.cambridge.org/zht/日誌相簿影音好友名片201505181453酒精對身體的不良反應alcoholethanolmetabolismkinetics?內科2018-01-22酒癮患者如果沒給thiamine先打葡萄糖水,會發生甚麼事情呢? 很多細胞因壓力或營養缺乏的關係,會發生upregulation.如果給予ATP前驅物(例如葡萄糖).這些細胞會迅速利用這些ATP前驅物.肝醣水解及TCA循環的酶,無法將反應繼續往前進行以產生ATP.導致中間產物堆積.反應式最終將往回走,結果不但ATP無法正常產生,反而將pyruvate轉換成乳酸,以維持肝糖水解,細胞將pyruvate轉換成乳酸的原因是要產生NAD+.以及淨產生兩個ATP, NAD+是肝醣水解步驟所需的物質,如果餵給細胞更多葡萄糖,而沒有給予thiamine,以使細胞反應完成ATP生成,只會增加乳酸生成.酸中毒的產生, 五碳糖磷酸途徑(pentosephosphatepathway,PPP)無法順利進行,進而使細胞受到活性氧類破壞細胞結構,細胞整體負載壓力上升,導致細胞死亡或啟動細胞凋亡機制. Whathappensifyoudonotgivethethiaminefirstbeforestartinganintravenousglucoseinfusion?Asstatedabove,manyofthesecellsandbiochemicalpathwaysmaybeupregulatedintimesofstressorwithnutritionaldeficiencies.Therefore,iftheyaregiventheprecursorsforATPproduction(suchasglucose),thenthesecellswillbegintorapidlyutilizethem.TheproblemcomesintheinabilityofthepreviouslydescribedenzymesofglycolysisandtheTCAcycletomovethereactionsforwardsothattheprecursor(i.e.,glucose)canbeutilizedtogeneratetheamountofATPthatitcannormallyproduce.Asaresult,intermediateproductswithinthepathwaysbegintoaccumulateandthesystemwilleventuallybackup.So,notonlyisATPfailingtobeadequatelygenerated,butpyruvateisaccumulatingasaresultofcontinuedglycolysis.TheinabilityofpyruvatetoentertheTCAcyclecausesthecelltoconvertthepyruvatetolactate(orlacticacid)inordertobeabletomaintainglycolysis.3,7ThereasonthecellconvertspyruvatetolactateistoregeneratetheNAD+requiredfortheprocessofglycolysistocontinueandtogenerateanetbalanceofatleast2ATP.3Therefore,asyoufeedthecellmoreglucosewithoutgivingtheneededthiaminetoallowfortheforwardmovementofcellularreactionsforcompleteATPgeneration,youonlyincreasetheamountoflacticacidproduced.Thisdevelopmentofacidosis,theinabilityofthepentosephosphatepathwaytoprotectthecellfromreactiveoxygenspeciesthatdamagecellularstructuresandthemountingstressonthecelloverall,resultsineithercelldeathoractivationofapoptosis.因此應