Sakurai T, Asakura T, Mizuno A, Matsuda M
Department of Biochemistry, Jikei University School of Medicine, Tokyo, Japan.
J Nutr Sci Vitaminol (Tokyo). 1991 Aug;37(4):341-8. doi: 10.3177/jnsv.37.341.
[3H]Pyridoxamine was orally administered to mice in physiological amounts, and the distribution of isotope between the six recognized forms of vitamin B6 and pyridoxic acid was determined at different times in the intestine, liver, blood, and brain. After 7 min about 50% of the radioactivity in pyridoxamine had been absorbed by the intestine and transported to the blood and other organs. Labeled pyridoxal phosphate was found in the intestine and liver. Labeled pyridoxamine could not be detected in the peripheral blood, but substantial amounts of labeled pyridoxal and pyridoxal phosphate were found in the blood. However, when a large amount (40-140 nmol) was given, a significant amount of labeled pyridoxamine was found in the blood, together with labeled pyridoxal and pyridoxal phosphate. These results suggest that the intestine and/or liver play a major role in completely converting physiological amounts of pyridoxamine to circulating pyridoxal, which is then taken up and phosphorylated by other organs.
以生理剂量给小鼠口服[³H]吡哆胺，在不同时间测定肠道、肝脏、血液和大脑中维生素B6的六种公认形式与吡哆酸之间的同位素分布。7分钟后，吡哆胺中约50%的放射性被肠道吸收并转运至血液和其他器官。在肠道和肝脏中发现了标记的磷酸吡哆醛。在外周血中未检测到标记的吡哆胺，但在血液中发现了大量标记的吡哆醛和磷酸吡哆醛。然而，当给予大量（40 - 140纳摩尔）时，在血液中发现了大量标记的吡哆胺，同时还有标记的吡哆醛和磷酸吡哆醛。这些结果表明，肠道和/或肝脏在将生理剂量的吡哆胺完全转化为循环中的吡哆醛方面起主要作用，然后其他器官摄取并将其磷酸化。
