不同时期高蛋白营养干预对宫内生长受限大鼠体成分和骨骼肌mTOR活性的影响  

Effects of High Protein Nutrition Intervention on Body Composition and Skeletal Muscle mTOR Activity of IUGR Rats during Different Periods

作　　者：余慕雪[1] 沈振宇[1] 莫清萍[2] 丘小汕[1] 

机构地区：[1]中山大学附属第一医院儿科,广州510080 [2]中山大学附属第一医院黄埔院区儿科,广东广州510080

出　　处：《中山大学学报（医学科学版）》2012年第6期749-755,共7页Journal of Sun Yat-Sen University:Medical Sciences

基　　金：广东省科技计划项目(2011B031800143;2009B060700038;2008B060600062)

摘　　要：【目的】探讨不同时期高蛋白营养干预对宫内生长受限(IUGR)大鼠体成分和骨骼肌哺乳动物雷帕霉素靶蛋白(mTOR)活性的影响。【方法】64只IUGR新生雄鼠出生时随机分为2组:IUGR对照组(CR)组40只、IUGR早期高蛋白干预组(EPR)组24只,另正常新生雄鼠24只为正常对照组(CN组)。4周龄时各组处理8只大鼠后CR组随机取16只大鼠组成IUGR延迟高蛋白干预组(DPR组)。3周哺乳期间CN组和CR组母鼠予基础饲料自由饮食,而EPR组母鼠予高蛋白饲料自由饮食;CN组和CR组断乳后予基础饲料自由饮食至12周龄,EPR组断乳后予高蛋白饲料自由饮食至4周龄、以后予基础饲料自由进食至12周龄;DPR组4～8周龄予高蛋白饲料、8～12周龄予基础饲料自由饮食。8、12周龄各组再处理8只大鼠。4、8、12周龄分别检测各组大鼠体成分、血清脂联素、血糖和胰岛素水平、骨骼肌纤维横截面积、骨骼肌mTOR活性。计算胰岛素抵抗指数(HOMA-IR)。【结果】与CN组相比,CR组4、8、12周龄和DPR组12周龄体脂肪百分比增加(P<0.05或P<0.01),而瘦体质量百分比、骨骼肌纤维横截面积、骨骼肌mTOR活性,血清脂联素水平减低(P<0.05或P<0.01)。CR组8、12周龄和DPR组12周龄HOMA-IR高于CN组(P<0.05或P<0.01)。与CR组相比,EPR组4、8、12周龄以及DPR组8周龄体脂肪百分比减低(P<0.05或P<0.01),而瘦体质量百分比、骨骼肌纤维横截面积、骨骼肌mTOR活性、血清脂联素水平增加(P<0.05或P<0.01)。EPR组8、12周龄和DPR组8周龄HOMA-IR低于CR组(P值均<0.01)。【结论】出生到4周龄是高蛋白营养干预IUGR大鼠较合适的关键时期,近期和远期均可改善其体成分和胰岛素敏感性,与高蛋白干预上调骨骼肌mTOR活性、促进瘦体质量增长而减少体脂成分有关。[Objective] To investigate the effects of high protein nutrition intervention on body composition and skeletal muscle mTOR （mammalian target of rapamycin） activity of IUGR （intrauterine growth restriction） rats during different periods. [ Methods] There were 64 male IUGR rats： 40 IUGR rats in the IUGR control group （CR group）, 24 IUGR rats in the early high protein intervention IUGR group （EPR group）. There were 24 normal birth weight male rats in normal control group （CN group）. At 4 weeks of age, 8 rats of these groups were executed and 16 rats in CR group were randomly assigned to the delay high protein intervention IUGR group （DPR group）. All rats were lactated for 3 weeks and the mother rats of CN and CR group were provided free access to basic diet while the mother rats of EPR group were provided free access to high protein diet. After weaning rats in CN and CR group were provided free access to basic diet until 12 weeks of age. After weaning rats in EPR group were provided free access to high protein diet until 4 weeks of age. At 4 weeks of age they were provided free access to basic diet until 12 weeks of age. Rats in DPR group were provided free access to high protein diet from 4 weeks of age to 8 weeks of age, and then they were provided free access to basic diet until 12 weeks of age. At 8, 12 weeks of age, 8 rats of these groups were executed. The body composition, serumadiponectin, blood glucose and insulin level, cross sectional area of skeletal muscle fibers, skeletal muscle mTOR activity were measured at 4, 8, 12 weeks of age. The homeostasis model assessment model for insulin resistance index （HOMA-IR） was calculated. [ Results ] The percentage of fat mass was significantly higher in the CR group than in the CN group at 4, 8, and 12 weeks of age and the DPR group at 12 weeks of age （P 〈 0.05 or P 〈 0.01）. The percentage of lean mass, cross sectional area of skeletal muscle fibers, skeletal muscle roTOR activity, serum adiponectin level were significantly lowe

关 键 词：宫内生长受限 体成分 高蛋白 MTOR 

分 类 号：R723[医药卫生—儿科]