高蛋白膳食对限食大鼠肠屏障功能的保护作用

目的:探讨高蛋白膳食对限食大鼠肠屏障功能的保护作用。方法:Wistar雄性大鼠,按体重随机分成五组:正常对照组,喂15%酪蛋白合成饲料,自由摄食;限食1组和2组分别按正常对照组摄食量的50%和30%对喂15%酪蛋白合成饲料;补蛋白1组和2组分别按正常对照组摄食量的50%和30%对喂30%酪蛋白合成饲料。实验2w后处死大鼠,取血和小肠组织进行检测。结果:补蛋白组与相应的限食组肠粘膜都有损伤,但前者损害较轻。限食组肠粘膜蛋白和DNA含量低于正常对照组,且有低于相应补蛋白组的趋势。限食组血清二胺氧化酶(DAO)活性、D-木糖水平比正常对照组显著升高,而补蛋白组则有高于正常对照组,低于相应的限食组的趋势。与正常对照组比,补蛋白组和限食组肠粘膜DAO活性都降低,但补蛋白组高于或显著高于相应的限食组。结论:高蛋白膳食能减轻限食对肠粘膜组织结构和功能的损害,对肠屏障功能有保护作用。

THE PROTECTIVE EFFECTS OF HIGH PROTEIN DIET ON INTESTINAL BARRIER FUNCTION IN FOOD RESTRICTED RATS

Objective: To study the protective role of high protein diet on the intestinal barrier function in food restricted rats. Method: Forty male Wistar rats were randomly divided into five groups: control group was given 15% casein diet ad-libitum; food restricted group 1 (FR1) and group 2 (FR2) were pair-fed 15% casein diet with 50% and 30% intake of control respecfively; protein supplemented group 1(SP1) and group 2(SP2) were pair-fed 30% casein diet with 50% and 30% intake of control respectively. Each group was fed for 2 w, then blood and intestinal samples were collected to examine the intestinal barrier function. Results: The histomorphology of intestinal mucosa manifested that the damages of intestinal tissue in SP groups were slighter than those in FR groups. The protein and DNA contents in intestinal mucosa of FR groups were lower than those in control group, and tendentiously lower than the corresponding SP groups. The serum diamine oxidase (DAO) activity and D-xylose level in FR group were significantly increased than those in control, but higher than the corresponding SP groups which were higher than control. The DAO activity in intestinal mucosa of SP protein groups was lower than that of control group, but significantly higher than the corresponding FR groups. Conclusion: High protein diet can reduce the damage of intestinal mucosa, and then protect the intestinal barrier function from injury induced by food restriction.