Arnaud S B, Goldsmith R S, Lambert P W, Go V L
Proc Soc Exp Biol Med. 1975 Jun;149(2):570-2. doi: 10.3181/00379727-149-38853.
Within 24 hr after intravenous administration of isotopic 25-hydroxyvitamin D3 to three normal adults for kinetic studies, one-third of the radioactivity was secreted into the lumen of the duodenum, probably with the bile. The subsequent intestinal reabsorption of over 85% of secreted radioactivity suggests that this major metabolite of vitamin D has a hitherto unrecognized enterohepatic circulation. Our observation of a dynamic hepatic secretion and intestinal reabsorption of radioactivity administered as 3H-labeled 25-hydroxyvitamin D3 to vitamin D-replete man is indicative of an enterohepatic circulation that may be of physiologic importance. It is conceivable that interruption in the recycling of 25-OH-D3 may be an important mechanism of acquired deficiency of vitamin D in gastrointestinal disease.
为进行动力学研究，给三名正常成年人静脉注射同位素标记的25-羟基维生素D3，在24小时内，三分之一的放射性物质分泌到十二指肠腔内，可能是随胆汁排出。随后，超过85%分泌出的放射性物质被肠道重吸收，这表明维生素D的这种主要代谢产物存在一种迄今未被认识的肠肝循环。我们对维生素D充足的人静脉注射3H标记的25-羟基维生素D3后观察到放射性物质在肝脏的动态分泌和肠道重吸收，这表明存在一种可能具有生理重要性的肠肝循环。可以想象，25-OH-D3循环的中断可能是胃肠道疾病中维生素D获得性缺乏的一个重要机制。
