富含精氨酸肠内营养对重度颅脑损伤大鼠免疫功能和蛋白代谢的影响

Effect of L-arginine enriched enteral nutrition on immunological function and protein metabolism in rats with severe brain trauma

目的:研究精氨酸对重度颅脑损伤大鼠的免疫功能和蛋白质营养状况的影响。方法:采用重度颅脑损伤大鼠模型,30只Wistar大鼠随机分为正常对照组(A组)、重度颅脑损伤后普通肠内营养支持(EN)组(B组)和重度颅脑损伤后EN+精氨酸(Arg)组(C组),每组10只。B组给予等量的酪氨酸,C组给予Arg 0.6 g.kg-1.d-1。早期(颅脑损伤后2 h)给予EN和EN+Arg,伤后9 d取外周血标本。采用吞噬白念珠菌计数法、链酶亲和素-生物素(SABC)法、放射免疫法分别测定白细胞吞噬功能、T细胞表型CD4+、CD8+含量、血清白细胞介-素2(IL-2)水平,用透射比浊法、溴甲酚绿法、双缩脲法分别检测血清前白蛋白(PA)、血清白蛋白(ALB)和总蛋白(TP)的含量。结果:重度颅脑损伤后B组和C组大鼠免疫功能和蛋白含量均有下降。C组大鼠的CD4+、CD4+/CD8+细胞比值I、L-2水平、白细胞吞噬率都高于B组(P均<0.05),B组大鼠的血清PA、ALB、TP含量与正常组比较明显降低(P均<0.05),C组大鼠的血清PA、ALB、TP含量接近A组(P均>0.05)。结论:重度颅脑损伤可导致大鼠细胞免疫功能下降和蛋白代谢紊乱,富含精氨酸的肠内营养能改善细胞免疫功能和蛋白代谢。

Objective：To observe the effects of L-arginine（Arg） enriched enteral nutrition on cellular immunological function and protein metabolism in rats with severe brain trauma.Methods：Thirty Wistar rats with severe brain trauma induced by gravity impact were divided randomly into 3 groups（n=10）：normal control group（group A）,enteral nutrition group（group B） and EN＋Arg group（group C）.Rats in groups B and EN ＋Arg were supplemented with tyrosine at the dose of 0.6 g·kg-1·d-1 and Arg at the dose of 0.6 g·kg-1·d-1 for 9 days respectively,then blood samples were collected after 9 days.Phagocytosis of white blood cells were analyzed with immunization methods,concentrations of CD4＋ and CD8＋ cells were analyzed by SABC,IL-2 level was measured by radioimmnoassay,contents of prealbumin（PA）,albumin（ALB） and total protein（TP） in serum were also determined with turbidimetry,bromcresol green method and biuret method,respectively.Results：Decreased cellular immunolgical function and protein content were found on the 9th day after severe brain trauma.However,CD4＋,CD4＋/CD8＋,IL-2 level,PMN phagocytosis rate in group C were higher than that in group B（P0.05）.Contents of PA,ALB and TP in group B were lower than that of group A（P all0.05）,while contents of PA,ALB and TP in group C were close to that of group A（P all0.05）.Conclusions：The cellular immunological function and protein metabolism were decreased in rats with severe brain trauma,which can be improved by L-arginine enriched enteral nutrition.