Iwata H, Yabushita Y, Doi T, Matsuda T
Neurochem Res. 1985 Jun;10(6):779-87. doi: 10.1007/BF00964535.
Thiamine metabolism in vivo was studied by intracerebroventricular injection of labeled thiamine in rat brain. Labeled thiamine was found to be rapidly converted to the phosphorylated thiamine esters. The distribution of the radioactive thiamine compounds was reached to steady state at 3 hr after injection: thiamine, thiamine monophosphate, thiamine pyrophosphate, and thiamine triphosphate were 8-12%, 12-14%, 72-74%, and 2-3%, respectively, in cerebral cortex. The presence of labeled thiamine triphosphate in the brain was further confirmed by the treatment with thiamine triphosphatase which had an absolute substrate specificity for thiamine triphosphate. These results suggest that thiamine triphosphate is synthesized in vivo in rat brain.
通过向大鼠脑室内注射标记的硫胺素，研究了硫胺素在体内的代谢情况。发现标记的硫胺素迅速转化为磷酸化的硫胺素酯。注射后3小时，放射性硫胺素化合物的分布达到稳态：在大脑皮层中，硫胺素、硫胺素单磷酸酯、硫胺素焦磷酸酯和硫胺素三磷酸酯分别占8 - 12%、12 - 14%、72 - 74%和2 - 3%。用对硫胺素三磷酸酯具有绝对底物特异性的硫胺素三磷酸酶处理，进一步证实了脑中存在标记的硫胺素三磷酸酯。这些结果表明，硫胺素三磷酸酯是在大鼠脑内体内合成的。
