Sakamoto K, Vucenik I, Shamsuddin A M
Department of Pathology, University of Maryland School of Medicine, Baltimore 21201.
J Nutr. 1993 Apr;123(4):713-20. doi: 10.1093/jn/123.4.713.
To understand the mechanism of antineoplastic action of phytic acid, we investigated the absorption and distribution of myo-[inositol-2-3H(N)] hexakisphosphate in rats. The radioactivity was measured in urine, feces, blood, gastrointestinal tract contents and various organs and tissues at 1 and 24 h after intragastric administration. Of the total radioactivity, 79.0 +/- 10.0% was absorbed and at least 26.6% was degraded during the 24-h period following ingestion. The absorption was rapid; 11.0 +/- 2.6% of the radioactivity was detected in the wall of the stomach (4.4 +/- 3.7%) and upper small intestine (6.6 +/- 1.9%), 6.5 +/- 2.6% in the skeletal muscle and 4.0 +/- 1.5% in the skin after 1 h. Much of the radioactivity after 24 h was in the liver (4.0 +/- 0.9%), kidneys (2.2 +/- 1.1%), muscle (18.1 +/- 3.4%) and skin (10.1 +/- 3.3%). Analysis of plasma and urine demonstrated that most of the radioactivity was due to myo-inositol and small amounts of inositol monophosphate (InsP1). Gastric epithelial cells, however, contained inositol and various inositol phosphates (InsP1-6). Our data suggest that soluble InsP6 when administered in drinking water is rapidly absorbed through the stomach and upper small intestine, becomes quickly dephosphorylated within the mucosal cells and is distributed to various organs as inositol and InsP1.
为了解植酸的抗肿瘤作用机制，我们研究了肌醇-[2-3H(N)]六磷酸在大鼠体内的吸收和分布情况。在胃内给药后1小时和24小时，对尿液、粪便、血液、胃肠道内容物以及各种器官和组织中的放射性进行了测量。在摄入后的24小时内，总放射性的79.0±10.0%被吸收，至少26.6%被降解。吸收迅速；给药1小时后，在胃壁（4.4±3.7%）和小肠上段（6.6±1.9%）中检测到11.0±2.6%的放射性，在骨骼肌中为6.5±2.6%，在皮肤中为4.0±1.5%。24小时后，大部分放射性存在于肝脏（4.0±0.9%）、肾脏（2.2±1.1%）、肌肉（18.1±3.4%）和皮肤（10.1±3.3%）中。血浆和尿液分析表明，大部分放射性来自肌醇以及少量的肌醇一磷酸（InsP1）。然而，胃上皮细胞中含有肌醇和各种肌醇磷酸（InsP1-6）。我们的数据表明，当通过饮用水给予可溶性InsP6时，它会迅速通过胃和小肠上段被吸收，在黏膜细胞内迅速去磷酸化，并以肌醇和InsP1形式分布到各个器官。
