EFFECT OF DEFICIENCY OF THIAMINE ON METABOLISM OF [U-C-14]GLUCOSE AND [U-C-14]RIBOSE AND LEVELS OF AMINO-ACIDS IN RAT-BRAIN
EFFECT OF DEFICIENCY OF THIAMINE ON METABOLISM OF [U-C-14]GLUCOSE AND [U-C-14]RIBOSE AND LEVELS OF AMINO-ACIDS IN RAT-BRAIN
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DOI：
10.1111/j.1471-4159.1974.tb12178.x
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发表时间：
1974-01-01
影响因子：
4.7
通讯作者：
SHARMAN, IM
中科院分区：
文献类型：
--
作者：
GAITONDE, MK;NIXEY, RWK;SHARMAN, IM
给补充硫胺素和缺乏硫胺素饮食的大鼠注射[U-14 C]葡萄糖和[U-14 C]核糖22天后，在不同时间测定脑中氨基酸的14 C掺入量。氨基酸标记结果表明，两组动物体内焦磷酸硫胺素需要酶、丙酮酸氧化酶、α-酮戊二酸脱氢酶和转酮醇酶的活性相似。有人认为，观察到的氨基酸标记的减少是由于以下一个或多个因素：（i）催化葡萄糖转化为磷酸丙糖的糖酵解酶活性的降低;（ii）底物向酶活性位点的转运减少;或（iii）脑神经组织病理学改变。硫胺素缺乏大鼠谷氨酸减少5%（P< 0-05），脑内苏氨酸含量降低46%（P<00 0 1），甘氨酸含量升高16%（P< 0-01）。
The incorporation of14C into amino acids of the brain was determined at different times after injection of [U‐14C]glucose and [U‐14C]ribose to rats maintained on thiamine‐supplemented and thiamine‐deficient diets for 22 days.The14C‐content of amino acids in the brain of thiamine‐deficient rats decreased at times 2–10 min after injection of [U‐14C]glucose. but it increased at 2 min and decreased at times 5–10 min after injection of [U‐14C]ribose.The results of labelling of amino acids indicated that the activitiesin vivoof the thiamine pyrophosphate requiring enzymes, pyruvate oxidase, a‐oxoglutarate dehydrogenase and transketolase were similar in the two groups. It was suggested that the observed decrease in the labelling of amino acids was due to one or more of the following factors: (i) a decrease in the activities of glycolytic enzymes catalysing the conversion of glucose into triose phosphate; (ii) a decrease in the transport of substrate to the active site of the enzymes; or (iii) altered neurohistopathology of the brain.Thiamine deficiency in rats showed a 5% decrease in glutamate (P< 0–05), 46% decrease in threonine(P< 0001) and 16% increase in glycine (P< 0–01) content of the brain.