Animal Nutrition Institute, Northeast Agricultural University, 150030 Harbin, Heilongjiang, China.
Biol Trace Elem Res. 2011 Oct;143(1):240-50. doi: 10.1007/s12011-010-8843-6. Epub 2010 Sep 17.
Synchrotron-based X-ray absorption fine structure (XAFS) spectroscopy is not widely used in animal science. The objective of this study was to employ the XAFS technique to determine changes in zinc absorption and concentrations in the sheep interstinal sac using different zinc sources. Forty-eight sheep were slaughtered and their duodena were dissected. The duodena were randomly assigned to six zinc sources (ZnO, ZnSO(4), ZnMet, ZnLys, ZnSO(4) + methionine, ZnSO(4) + lysine). Ten centimeters of duodenal sac midpiece was incubated for 40 min in vitro using the everted intestinal sac technique in culture medium containing zinc from different sources. The amount of zinc present was normalized to 4 mg. XAFS was used to analyze the relative concentration and oxidation state of zinc, and atomic absorption spectrometry (AAS) was used to verify zinc concentration. The results showed that, for increasing zinc concentrations, organic zinc was a better source than inorganic zinc. In addition, the zinc concentration achieved using ZnMet was higher than that for ZnO and ZnSO(4) (P < 0.05) as measured by atomic absorption spectroscopy. The results using XAFS were consistent with that of AAS. The states of organic zinc and inorganic zinc were identical after being incubated for 40 min. As observed in these experiments, organic zinc was more easily absorbed than inorganic zinc. Our data demonstrate that organic zinc was dissociated into ions and then absorbed as inorganic zinc. In our experiments, we are the first investigators to use XAFS spectroscopy to determine zinc absorption in the sheep duodenal wall. We observed reduced absorption of inorganic zinc in the presence of methionine or lysine. Taken together, we postulate that the optimal molar ratio of inorganic zinc and ligand requires further study.
基于同步加速器的 X 射线吸收精细结构（XAFS）光谱学在动物科学中并未得到广泛应用。本研究的目的是采用 XAFS 技术，使用不同的锌源来确定绵羊肠道囊中锌的吸收和浓度变化。将 48 只绵羊屠宰并解剖其十二指肠。将十二指肠随机分配到 6 种锌源（ZnO、ZnSO4、ZnMet、ZnLys、ZnSO4+蛋氨酸、ZnSO4+赖氨酸）中。使用外翻肠囊技术，在含有不同来源锌的培养基中，将十二指肠中段 10cm 进行 40min 的体外孵育。将锌的含量归一化为 4mg。使用 XAFS 分析锌的相对浓度和氧化态，原子吸收光谱法（AAS）用于验证锌浓度。结果表明，随着锌浓度的增加，有机锌比无机锌更具优势。此外，使用 ZnMet 获得的锌浓度高于 ZnO 和 ZnSO4（P＜0.05），这一点通过原子吸收光谱法得到了验证。XAFS 的结果与 AAS 的结果一致。经过 40min 的孵育，有机锌和无机锌的状态相同。在这些实验中观察到，有机锌比无机锌更容易被吸收。我们的数据表明，有机锌先被分解为离子，然后被吸收为无机锌。在我们的实验中，我们首次使用 XAFS 光谱法来确定绵羊十二指肠壁中的锌吸收情况。我们观察到在存在蛋氨酸或赖氨酸的情况下，无机锌的吸收减少。总的来说，我们假设无机锌和配体的最佳摩尔比需要进一步研究。
