Chowrimootoo G, Debnam E S, Srai S K, Epstein O
Department of Physiology, Royal Free Hospital, School of Medicine, London.
Exp Physiol. 1992 Jan;77(1):177-83. doi: 10.1113/expphysiol.1992.sp003571.
Features of iron absorption by the upper small intestine and ileum in the adult guinea-pig have been compared. Autoradiographic methods have revealed that whilst only upper villus enterocytes in the duodenum-jejunum are involved in brush-border uptake, the entire villus epithelium in the ileum displays this function. Consistent with these results was the finding that brush-border membrane vesicles prepared from ileal mucosa demonstrated a higher capacity for iron uptake (expressed per mg protein) compared to vesicles of duodenal origin. Iron transport to blood following 30 min exposure of mucosa to 59Fe-ascorbate was some elevenfold higher in upper, compared to lower, small intestine. The relevance of these findings to our knowledge of the cellular processes involved in intestinal iron absorption and its regional localization is discussed.
对成年豚鼠上段小肠和回肠铁吸收的特征进行了比较。放射自显影方法显示，虽然十二指肠-空肠中只有上段绒毛肠上皮细胞参与刷状缘摄取，但回肠的整个绒毛上皮都具有这种功能。与这些结果一致的是，从回肠黏膜制备的刷状缘膜囊泡与十二指肠来源的囊泡相比，显示出更高的铁摄取能力（以每毫克蛋白质表示）。黏膜暴露于59Fe-抗坏血酸30分钟后，上段小肠向血液转运的铁比下段小肠高出约11倍。讨论了这些发现与我们对肠道铁吸收及其区域定位所涉及的细胞过程的认识的相关性。
