Mykkanen H M, Fullmer C S, Wasserman R H
J Nutr. 1984 Jan;114(1):68-74. doi: 10.1093/jn/114.1.68.
The effect of phosphate on the intestinal absorption of lead (203Pb2+) was examined in chicks. Absorption was determined by the in situ ligated duodenal loop technique. In one approach, diets differing in phosphate content were fed to 2-week-old chicks for a period of 7 days. With respect to the control group (1.06% P), a severe phosphate deficiency (0.16% P) decreased growth, CaBP synthesis and 203Pb absorption; a moderate phosphate deficiency (0.33% P) resulted in an increase in CaBP production and 203Pb absorption; and the high phosphate diet (2.12%) gave mean values for CaBP synthesis and 203Pb absorption intermediate between those from the chicks fed the 0.33 and 1.06% diets. 203Pb absorption was highly correlated with CaBP concentrations. In another approach, phosphate in varying concentrations was added directly to the dosing solution. In one study, phosphate addition (0.1 mM) depressed 203Pb absorption in rachitic and cholecalciferol-treated chicks. When the data were expressed in terms of absorption of the soluble 203Pb present in the intestinal lumen at the end of the absorption period, an effect of phosphate in addition to the precipitation of the insoluble lead salt was uncovered. In an experiment with normal chicks, it was observed that phosphate in the dosing solution at concentrations of 1 and 2 mM partially and significantly reversed the inhibitory effect of lower concentrations of phosphate (0.01 mM and 0.1 mM). These data demonstrate the complexity of the phosphate-lead interaction, in addition to directly showing an effect of dietary phosphate on intestinal lead absorption.
在雏鸡中研究了磷酸盐对肠道铅（²⁰³Pb²⁺）吸收的影响。采用原位结扎十二指肠袢技术测定吸收情况。在一种方法中，将含磷量不同的日粮喂给2周龄雏鸡7天。相对于对照组（1.06%磷），严重缺磷（0.16%磷）会降低生长、钙结合蛋白（CaBP）合成及²⁰³Pb吸收；中度缺磷（0.33%磷）会导致CaBP生成及²⁰³Pb吸收增加；高磷日粮（2.12%）使CaBP合成及²⁰³Pb吸收的平均值介于喂食0.33%和1.06%日粮的雏鸡之间。²⁰³Pb吸收与CaBP浓度高度相关。在另一种方法中，将不同浓度的磷酸盐直接添加到给药溶液中。在一项研究中，添加磷酸盐（0.1 mM）会降低佝偻病雏鸡和经胆钙化醇处理雏鸡的²⁰³Pb吸收。当数据以吸收期结束时肠腔内可溶性²⁰³Pb的吸收量表示时，发现除了不溶性铅盐沉淀外，磷酸盐还有其他作用。在一项针对正常雏鸡的实验中，观察到给药溶液中浓度为1 mM和2 mM的磷酸盐部分且显著地逆转了较低浓度磷酸盐（0.01 mM和0.1 mM）的抑制作用。这些数据表明了磷酸盐 - 铅相互作用的复杂性，同时也直接显示了日粮磷酸盐对肠道铅吸收的影响。
