围生期宫内生长迟缓胎鼠的发育及其肝胰岛素信号转导蛋白的表达

目的:研究大鼠妊娠期营养不良对围生期胎鼠肝胰岛素信号转导蛋白表达的影响.方法:饥饿组雌性大鼠受孕后第1天控制进食鼍为对照组的50%至分娩,从而建立宫内生长迟缓(intrauterine growth retardation,IUGR)大鼠模型.于雌性大鼠妊娠第15、17、19、21天(E15、E17、E19、E21)取胎,称量胎鼠体重,胎盘、胎鼠肝、脑的重量,计算胎盘重/体重(placenta weight/body weight ratio,PWR)、肝重/体重(liver weight/body weight ratio,LWR),脑重/体重(brain weight/body weight ratio,BWR)的比值;RT-PCR检测E15,E17,E19,E21及生后第1天(P1)新生大鼠肝胰岛素受体(insulin receptor,IR)、胰岛素受体底物-1(insulin receptor substrate-1,IRS-1)、胰岛素受体底物-2(insulin receptor substrate-2,IRS-2)、磷脂酰肌醇3激酶(phosphatidyl inositol 3-kinase,PI3K)mRNA的表达.结果:(1)IUGR胎鼠E15时PWR低于对照组,E17后PWR逐渐增加(P<0.05);IUGR组E15胎鼠的LWR值与对照组相比,差异无统计学意义,E17～E21则明显下降(P<0.05);IUGR胎鼠平均BWR水平高于对照组(P<0.05);(2)IUGR胎鼠肝IRS-1 mRNA的表达在E15、E17与对照相似,E19则下降(P<0.05),并持续低表达至P1(P<0.05);E15 IUGR胎鼠肝IRS-2 mRNA的表达已显著减少,并持续到P1(P<0.05);围生期IUGR胎鼠肝IR mRNA,PI3KmRNA的表达与对照组相近(P0.05).结论:(1)雌性大鼠妊娠期饥饿致胎盘、胎鼠体重、肝、脑组织重量下降,以体重和肝为著,使肝重与体重比值下降而脑重与体重的比值增加,即"脑保护效应";(2)雌性大鼠妊娠期营养不良仔大鼠围生期肝胰岛素信号转导蛋白IR mRNA、PI3K mRNA的表达尚未明显受损;但IRS-1 mRNA和IRS-2mRNA呈低水平表达,可能与其生长迟缓及成年期胰岛素抵抗有关.

Expression of the hepatic insulin signal transduction proteins in the rats with intrauterine growth retardation during the perinatal period

Objective:To investigate the effects of maternal malnutrition on the expression of the insulin signal transduction proteins in the liver of perinatal rats.Methods:(1)The dams were semi-starvation from the first day during pregnancy to build the animal model of intrauterine growth retardation(IUGR).On days 15,17,19,21(E15,E17,E19,E21)of gestation,the fetuses were delivered by cesarean section.The fetal rats,placenta,fetal liver and the fetal brain were weighed respectively.And the placenta weight to the body...