Sheehan R G
Am J Physiol. 1976 Nov;231(5 Pt. 1):1438-44. doi: 10.1152/ajplegacy.1976.231.5.1438.
To define the significance of the uptake step by unidirectional uptake of iron was measured on proximal small intestintestinal segments from Nembutal-anesthetized rats. The method employed a nonabsorbable marker of adherent incubating medium, and the studies were performed during the linear time period of instantaneous uptake. Uptake was linear over the concentration range 0.1-10 mM, from three iron complexes. The rate varied with the bioavailability of the iron in each complex. The Q10 was 1.0-1.3. Uptake rates were similar in all segments of small intestine. Uptake was not increased in segments from iron-deficient animals or rats with hemolytic anemia. Cobalt did not inhibit the uptake rate. These studies demonstrate that the uptake of nonheme iron by the small intestinal mucosal cell is by passive diffusion and further indicate that the uptake step does not contribute significantly to the mucosal control of iron absorption.
为了通过测量戊巴比妥麻醉大鼠近端小肠段的铁单向摄取来确定摄取步骤的意义。该方法使用了附着孵育培养基的不可吸收标记物，并且研究是在瞬时摄取的线性时间段内进行的。从三种铁络合物中摄取在0.1 - 10 mM的浓度范围内呈线性。速率随每种络合物中铁的生物利用度而变化。Q10为1.0 - 1.3。小肠各段的摄取速率相似。缺铁动物或溶血性贫血大鼠的肠段摄取并未增加。钴不抑制摄取速率。这些研究表明，小肠黏膜细胞对非血红素铁的摄取是通过被动扩散，并且进一步表明摄取步骤对铁吸收的黏膜控制没有显著贡献。
