左旋精氨酸对低出生体重仔鼠PI3K和PKB的影响  

Effects of L-Arg on expression of PI3K and PKB in liver among low-birth-weight newborn rats

作　　者：罗开菊[1] 陈平洋[1] 谢宗德[1] 李雯[1] 李素萍[1] 贺鸣凤[1] 

机构地区：[1]中南大学湘雅二医院新生儿科,湖南长沙410011

出　　处：《中国当代儿科杂志》2013年第8期682-685,共4页Chinese Journal of Contemporary Pediatrics

基　　金：湖南省科技计划一般项目(No.2007SK3042)

摘　　要：目的生命早期应用左旋精氨酸(L-Arg)干预低出生体重仔鼠,检测其肝脏磷脂酰肌醇-3-激酶(PI3K)和蛋白激酶B(PKB)的表达,探讨L-Arg对改善胰岛素抵抗的影响。方法以孕期低蛋白饮食法建立低出生体重仔鼠模型,18只孕鼠随机分为对照组、模型组和干预组,每组6只。对照组孕期给予21%正常蛋白饲料建立正常出生体重仔鼠模型,模型组及干预组孕期给予10%低蛋白饲料建立低出生体重仔鼠模型,3组孕鼠所生仔鼠分别纳入仔鼠对照组、模型组、干预组。生后21 d仔鼠的哺乳期内,3组孕鼠均给予21%正常蛋白饲料喂养,对照组及模型组给予正常饮用水喂养,干预组给予富含L-Arg(200 mg/kg.d)的饮用水喂养。断乳后,3组仔鼠均给予21%正常蛋白饲料及正常饮用水喂养。于仔鼠生后1周、3周、8周时,分别留取3组仔鼠的肝脏标本,用Western blot法检测肝脏PI3K和PKB的蛋白表达。结果 1周时干预组仔鼠肝脏PI3K的蛋白表达高于模型组(P=0.045),且与正常组相比差异无统计学意义(P=0.503)。8周时干预组仔鼠肝脏PKB蛋白表达明显高于模型组(P=0.039),且与正常组比较差异无统计学意义(P>0.05)。结论生命早期补充L-Arg可促进蛋白质的合成,增加肝脏PI3K及PKB的蛋白表达,促进胰岛素信号传导,改善胰岛素抵抗。Objective To measure the expression of phosphatidylinositol 3-kinase （PI3K） and protein kinase B （PKB） in liver tissue among low-birth-weight newborn rats treated with L-arginine （L-Arg） in early life, and to investigate the effect of L-Arg on insulin resistance. Methods Eighteen pregnant rats were randomly divided into three groups： control, model and intervention （n=6 each）. The control group was fed with normal protein feed （protein content=21%） during pregnancy to establish a normal-birth-weight newborn rat model, and the model and intervention groups were fed with low-protein feed （protein content=-10%） during pregnancy to establish a low-birth-weight newborn rat model. Newborn rats from the three pregnant rat groups were also assigned to control, model and intervention groups. During 21 days of lactation, maternal rats in the control and model groups were fed with normal protein feed and normal drinking water, while maternal rats in the intervention group were fed with normal protein feed and drinking water rich in L-Arg （200 mg/kg.d）. After ablactation, the three groups of newborn rats were fed with normal protein feed and normal drinking water. Liver tissue samples were collected from these newborn rats at 1, 3 and 8 weeks after birth. Protein expression of PI3K and PKB in liver tissue was measured by Western blot. Results At 1 week after birth, the newborn rats in the intervention group had significantly higher protein expression of PI3K than in the model group （P=0.045）, but there was no significant difference when compared with the control group （P=0.503）. At 8 weeks after birth, the newborn rats in the intervention group had significantly higher protein expression of PKB than the model group （P=0.039）, but there was no significant difference when compared with the control group （P〉0.05）. Conclusions A supplement of L-Arg in early life can boost protein synthesis, increase protein expression of PI3K and PKB in liver tissue, promote insulin signaling and r

关 键 词：左旋精氨酸 低出生体重 肝脏 胰岛素信号传导 胰岛素抵抗 大鼠 

分 类 号：R722.1[医药卫生—儿科]