高蛋白膳食对限食大鼠血清和肠粘膜氨基酸谱的影响

目的探讨高蛋白膳食对限食大鼠血清和肠粘膜氨基酸谱的影响。方法 Wistar雄性大鼠,按体重随机分成五组,分别为正常对照组,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,取血和小肠组织检测游离氨基酸含量。结果限食组和补蛋白组的大鼠血清游离氨基酸浓度均低于正常对照组,并且除了甘氨酸和胱氨酸外均有统计学意义(P<0.05),其中苯丙氨酸、酪氨酸、亮氨酸、异亮氨酸、缬氨酸、谷氨酸下降最为明显(P<0.01);而补蛋白组的大鼠血清游离氨基酸浓度又高于相应的限食组,其中苯丙氨酸、酪氨酸、亮氨酸、异亮氨酸、缬氨酸、精氨酸、谷氨酸有显著性差异(P<0.05)。限食组和补蛋白组的大鼠肠粘膜游离氨基酸含量均低于正常对照组,其中苯丙氨酸、酪氨酸、亮氨酸、异亮氨酸、缬氨酸、精氨酸、谷氨酸有显著性差异(P<0.05);而补蛋白组的大鼠肠粘膜游离氨基酸含量又高于相应的限食组,其中亮氨酸、异亮氨酸、缬氨酸、精氨酸、谷氨酸有显著性差异(P<0.05)。结论提高膳食中的蛋白质比例能降低限食对大鼠血清和肠粘膜氨基酸谱的影响,改善血清氨基酸代谢。

EFFECTS OF HIGH PROTEIN DIET ON AMINO ACID PROFILE IN BLOOD AND INTESTINAL MUCOSA IN FOOD RESTRICTED RATS

Objective To study the effects of high protein diet on amino acid profile in blood and intestinal mucosa in food restricted rats.Method Forty male Wistar rats were randomly divided into five groups:(1) Control group was given 15% casein synthetic diet ad-libitum;(2) Food restricted group 1(FR1) and(3) Food restricted group 2(FR2) were pair-fed 15% casein synthetic diet with 50% and 30% intake of control respectively;(4) Protein supplemented group 1(SP1) and(5) Protein supplemented group 2(SP2) were pair-fed 30% casein synthetic diet with 50% and 30% intake of control respectively.Each group was fed 2 w,and then blood and intestinal samples were collected to examine the content of free amino acids.Results The concentrations of serum free amino acids except glycine and cystine in food restricted groups and protein supplemented groups were all significantly lower than normal control(P<0.05),and the levels of phenylalaine,tyrosine,isoleucine,leucine,valine and glutamic acid decreased highly significantly(P<0.01).Moreover,serum free amino acid concentrations increased,such as phenylalaine,tyrosine,isoleucine,leucine,valine,arginine and glutamic acid increased significantly in protein supplemented groups compared with corresponding food restricted groups(P<0.05).Furthermore,the changes of free amino acids in intestinal mucosa had the same tendency.The contents of phenylalaine,tyrosine,isoleucine,leucine,valine and glutamic acid in food restricted groups and protein supplemented groups decreased significantly compared with normal control(P<0.05).And the contents of free amino acids in protein supplemented groups arose compared with homologous food restricted groups,and isoleucine,leucine,valine and glutamic acid increased significantly (P<0.05).Conclusion Increased protein content of the feed can correct the amino acid profile in blood and intestinal mucosa in food restricted rats.