中文摘要：

目的本研究应用高效液相色谱法（high performance liquid chromatography．HPLC），检测幼兔尿液中乳果糖、甘露醇含量，计算其排出率比值，探讨双歧杆菌对肠外营养幼兔肠道通透性的影响。方法2周龄新西兰种白兔21只，分为3组，对照组6只，PN组8只，PN＋双歧杆菌7只。对照组幼兔为母乳喂养，PN组幼兔完全肠外营养，PN＋双歧组幼兔经胃管予青春双歧杆菌0．5×10^8，共10d。于第九天分别经胃管予3组幼兔灌服乳果糖和甘露醇溶液2ml（含乳果糖100mg，甘露醇50mg）。收集24h尿液。经处理后应用高效液相离子色谱法检测尿中乳果糖、甘露醇含量，分别计算排出率及其比值。结果上述色谱条件下，尿液中甘露醇和乳果糖能得到良好分离。该法检测上述2种糖的日内精密度：乳果糖为3．03％～3．57％，甘露醇为2．40％～3．31％；日间精密度：乳果糖为3．43％～4．0％，甘露醇为1．73％～2．84％。乳果糖和甘露醇加样回收率分别为99．6％～100．7％和97．3％～100．7％。3组尿液中乳果糖排出率分别为0．019±0．005、0．099±0．022和0．025±0．01，甘露醇排出率分别为1．142±0．17、2．43±0．24和1．147±0．67，比值分别为0．019±0．005、0．038±0．008和0．020±0．004。结论高效液相离子色谱法能够快速、简单、灵敏地测定幼兔尿中乳果糖、甘露醇含量；双歧杆菌能够降低肠外营养幼兔肠道通透性。

英文摘要：

Objective To study the effects of bifidobacteria on the gastrointestinal permeability of infant rabbits receiving parenteral nutrition, via measurement of lactulose and mannitol in urine with HPLC. Methods Two-week-old New Zealand white rabbits, weight ranged form 200 g to 250 g, were divided into three experimental groups： （1） Control group（n = 6） ; （2） PN group（n = 8） ; （3） PN ＋ Bif group（n = 7）. PN ＋ Bif rabbits were gavaged with a solution of bifidobacteria （0. 5 × 10^8/d） through oral-stomach catheter for 10 days. Two milliliter of mixture of lactulose and mannitol, containing 100 mg of lactulose and 50 mg of mannitol, are orally administered on the 9^th day, and after 24 h, the urine samples were collected. The HPLC method was undertaken to measure the contents of lactulose and mannitol. The related ratios were calculated. Results Under conditions above, the separation of lactulose and mannitol was rational. The intra-assay precision （CV） was 3.03 % - 3. 57 % for lactulose or 2. 40% - 3.31% for mannitol. Inter-assay CVs were 3.43% - 4. 0% and 1.73% - 2. 84% for lactulose and mannitol, respectively. The recovery rates of lactulose and mannitol were 99. 6% - 100. 7% and 97. 3%- 100. 7%, respectively. The lactulose/mannitol ratio in control subjects was 0. 019 ± 0. 005 ; in PN and PN ＋ Bif rabbits, the ratios were 0. 038 ±0. 008 and 0. 020±0. 004, respectively. Conclusions HPLC is a rapid, simple and sensitive method to detect the concentration of lactulose and mannitol. Intestinal barrier function is significantly decreased by bifidobacteria in PN infant rabbits.