Bitsch R, Hansen J, Hötzel D
Int J Vitam Nutr Res. 1982;52(2):126-33.
The effect of ethanol administration on the phosphorylation of thiamin, and on the transketolase activity (TKA) in erythrocytes, heart and liver, and on the thiamin excretion in urine was investigated in rats optimally supplied with thiamin over a period of 16 weeks. Ethanol ingestion resulted in a diminished concentration of thiamin (T), thiaminmonophosphate (TMP), thiamindiphosphate (TDP) and thiamintriphosphate (TTP) in blood and organs and in a reduced excretion rate of T in urine due to an impaired intestinal absorption. An ethanol induced alteration of the degree of thiamin phosphorylation became evident only after 16 weeks resulting in a decline of T and TMP in blood and of T in heart to undetectable amounts and in an enhancement of the TDP- and TTP-pool. Despite an increasing content of TDP in erythrocytes the TKA was lowered and the alpha-TK was enhanced during the test period suggesting a partially inhibited formation of the active holoenzyme by alcohol in vivo. However, the lowered TKA and the normal alpha-TK in liver are primarily suggestive of an apo-enzyme degeneration influenced by ethanol.
在为期16周的时间里，对硫胺素供应充足的大鼠研究了乙醇给药对硫胺素磷酸化、红细胞、心脏和肝脏中转酮醇酶活性（TKA）以及尿中硫胺素排泄的影响。摄入乙醇导致血液和器官中硫胺素（T）、硫胺素一磷酸（TMP）、硫胺素二磷酸（TDP）和硫胺素三磷酸（TTP）浓度降低，且因肠道吸收受损导致尿中T排泄率降低。乙醇诱导的硫胺素磷酸化程度改变仅在16周后才明显，导致血液中T和TMP以及心脏中T降至无法检测的水平，同时TDP和TTP池增加。尽管红细胞中TDP含量增加，但在试验期间TKA降低而α-TK升高，这表明体内酒精部分抑制了活性全酶的形成。然而，肝脏中降低的TKA和正常的α-TK主要提示乙醇影响了脱辅基酶的变性。
