硒在肉仔鸡小肠中的吸收规律及其机制研究

In the present project, experiments half in vivo with in situ ligated small intestinal loops of broilers will be conducted to investigate the absorption traits and kinetics of selenium (Se) in the form of inorganic sodium selenite in ligated duodenal, jejunal and ileal segments, and the effect of Se treatment on mRNA and protein expression levels of differential proteins in these ligated small intestinal segments by using the techniques of proteomics, RT-PCR and western blotting. The objectives of the present project will be to systematically and deeply elucidate the absorption traits of Se in the small intestine of broilers and its mechanisms. The outcomes from this project will enrich and develop the current theory and knowledge of Se nutrition in broilers, and provide new and scientific experimental basis and methods for how to improve dietary Se absorption and utilization, insure the Se nutrition as well as healthy and efficient production, decrease the supplemental level of dietary Se and minimize the environmental pollution of Se excreted by broilers in the broiler production.

本项目拟通过肉仔鸡半体内原位结扎灌注小肠段试验，研究无机亚硒酸钠形态硒在肉仔鸡结扎十二指肠、空肠、回肠段中的吸收规律和吸收动力学模式，并应用蛋白质组学、RT-PCR和Western blotting技术研究无机亚硒酸钠形态硒对肉仔鸡结扎十二指肠、空肠、回肠段中差异蛋白mRNA及其翻译蛋白表达的影响，从而系统、深入揭示硒在肉仔鸡小肠中的吸收规律及其机制，丰富和发展肉鸡硒营养的现有理论和知识，并为养鸡生产中如何提高硒吸收利用，确保鸡体硒营养及其健康和高效生产，同时减少饲粮硒添加及硒排放对环境的污染，提供新的科学试验依据和方法、途径。

本项目通过肉仔鸡半体内原位结扎灌注小肠段试验，研究了无机亚硒酸钠形态硒在肉仔鸡结扎十二指肠、空肠和回肠段中的吸收规律和吸收动力学模式，采用蛋白质组学技术及RT-PCR和平行反应监测(PRM)靶向定量技术筛选了不同硒水平下肉仔鸡十二指肠粘膜中差异表达蛋白并对其进行了验证，获得了国内外文献中均未见报道的创新研究成果：(1)发现灌注液中硒水平为0.30-0.60μg/mL时，空肠是肉仔鸡小肠中硒吸收的主要部位，回肠和十二指肠次之，且硒在十二指肠中的吸收以饱和载体转运为主，而在空肠和回肠中的吸收则以非饱和扩散为主；(2)通过蛋白质组学技术筛选获得了十二指肠粘膜中4164个可定量的差异蛋白，根据差异蛋白的功能和特性从中筛选了21个目的蛋白做进一步验证；(3)用RT-PCR和PRM技术分别从mRNA和蛋白表达水平验证发现，F1P3D8(溶质载体家族成员25)、F1NTZ0(乙醇脱氢酶6)和F1NXH1(未定义蛋白)可能参与了肉仔鸡十二指肠中硒的吸收。以上研究新成果揭示了硒在肉仔鸡小肠中的主要吸收部位和方式，并初步揭示了其分子机制，丰富和发展了肉鸡硒营养的现有理论和知识，并为养鸡生产中如何提高硒的高效吸收和利用，确保鸡体硒营养和健康，提供了新的科学试验依据。