肿瘤坏死因子对谷氨酰胺调控大鼠骨骼肌蛋白质合成的影响  

Tumor necrosis factor-α regulates the effect of glutamine on protein synthesis in rats' skeletal muscle

作　　者：周济宏[1] 李幼生[2] 解伟光[1] 曹亚澄[3] 韩勇[3] 黎介寿[2] 

机构地区：[1]南京军区南京总医院烧伤整形外科,江苏南京210002 [2]南京军区南京总医院解放军普通外科研究所,江苏南京210002 [3]中国科学院土壤研究所,江苏南京210008

出　　处：《医学研究生学报》2006年第10期884-887,共4页Journal of Medical Postgraduates

基　　金：国家自然科学基金资助项目(批准号:30271263)

摘　　要：目的:研究促炎细胞因子肿瘤坏死因子α(TNF-α)对谷氨酰胺(G ln)调控大鼠骨骼肌蛋白质合成的影响。方法:雄性SD大鼠30只,随机分为三组:完全肠道外营养(TPN)组,TPN+G ln组和TPN+G ln+TNF-α组。每组各10只大鼠,三组大鼠均行72 h TPN。TPN+G ln组加用丙氨酰谷氨酰胺二肽,提供的G ln剂量为0.3g/(kg.d),共72 h。TPN+G ln+TNF-α组在实验结束前24 h持续静脉滴注TNF-α,速度为5μg/(kg.h),并加入丙氨酰谷氨酰胺二肽(用法同TPN+G ln组)。三组所供营养液氮(N)量、热量均等。所有大鼠均在取材前30 m in一次性静脉注射[L1-5N]亮氨酸,剂量为1.0mmol/kg。分别测定血浆中TNF-α浓度、血浆及组织中G ln浓度,并测定骨骼肌组织的蛋白质合成率。结果:血浆及骨骼肌组织中G ln浓度,TPN组低于TPN+G ln组,两组均低于TPN+G ln+TNF-α组;骨骼肌蛋白质合成率TPN组最低,TPN+G ln组最高。以上各组之间差异均具有显著性意义(P<0.01)。结论:TNF可升高血浆及骨骼肌组织中G ln的浓度;G ln能促进骨骼肌蛋白质合成;而G ln这种促骨骼肌蛋白质合成作用可被TNF-α抑制。Objective ：To find the regulations of glutamine （Gln） metabolism by tumor necrosis factor-α （TNF-α）. Methods：Thirty male SD rats were assigned into three groups： A （total parenteral nutrition, TPN）, B （TPN ＋ Gln）, C （TPN ＋ TNF-ct ＋Gln）. Besides all rats were supported by isonitrogenous and isocaloric TPN solutions for 3 days, rats in group B were supplied with Gln （in the form of alanylglutamine） for 3 days at the rate of 0.3 g/（kg· d）, rats in group C were infused intravenously with TNF-α at the rate of 5 μg/（kg·h） within the last 24 hours and also supplemented with Gln for three days at thesame rate as in group B. At the last 0.5 hour, all animals were mainlined with [ L-^15 N ] leucine at the dosage of 1.0 mmol/kg. TNF-α levels in plasma, concentrations of Gin in plasma and skeletal muscle were measured as the experiment ended after 72 hours, and the fractional synthesis rate （FSR） were also assessed. Results：The Gin concentrations in plasma and skeletal muscle increased markedly from group A, B to C. The levels of FSR decreased remarkably along with the sequence from group B, C to A. The statistical differences were significant （P 〈 0.01 ）. Conclusion ： The results indicated that TNF-α could increase the levels of Gin in plasma and skeletal muscle, and attenuate the promotion of protein synthesis by Gin in skeletal muscle.

关 键 词：谷氨酰胺 蛋白质合成率 稳定性核素 [L-^15N]亮氨酸 肿瘤坏死因子Α 

分 类 号：R392.11[医药卫生—免疫学]