应用XAFS研究十二指肠中锌的相对浓度和状态

Study of Zn relative concentration and state in duodenal by XAFS

试验采用外翻肠囊方法,以不同锌源(ZnO、ZnSO_4、ZnMet、ZnLys、ZnSO_4+Met、ZnSO_4+Lys)为处理因素,体外密闭培养绵羊十二指肠40 min,应用XAFS技术分析十二指肠肠囊中锌浓度和状态。试验结果表明:就提高十二指肠肠囊中锌浓度而言,有机锌明显优于无机锌,十二指肠肠囊中有机锌的吸收机理与无机锌的相同,通过不依赖于载体调节的非饱和扩散被吸收的,解离成离子后通过无机锌的吸收途径被吸收。此外,本试验条件下,无机锌与配体蛋氨酸及赖氨酸的结合反而抑制了锌元素的吸收。本研究开创了应用同步辐射研究锌动物营养先河,并且确定了有机锌在绵羊十二指肠肠道中的吸收机理,为有机锌和无机锌的合理应用提供了依据。

Everted intestinal sac method was used in this study. The sheep duodenum was cultured for 40 rain in vitro, with different sources of zinc （ZnO, ZnS04, ZnMet, ZnLys, ZnSO4 ＋ Met, ZnSO4 ＋ Lys）. XAFS technical was used to analyze the relative concentration and state of zinc in duodenal sac. The results showed that： For increasing zinc concentration in duodenal sac, organic zinc was obviously better than inorganic zinc in the treatment, the absorption mechanisms of organic and inorganic zinc were the same in duodenal sac, zinc element was absorbed by independent of carrier regulative unsaturated proliferation, and then it was dissociated into ions, was absorbed by means of inorganic zinc. In addition, absorption of zinc element was inhibit by the combination of inorganic zinc and the ligands of methionine and lysine. XAFS technology had not been used for researching animal zinc nutrition before our experiment, and the absorption mechanism of organic zinc in the duodenum of sheep was determined. The reasonable application foundation of organic zinc and inorganic zinc was provided.