早期营养对IUGR大鼠糖耐量和胰岛素敏感性的远期影响

Long-Term Effects of Early Nutrition on Glucose Tolerance and Insulin Sensitive Index of IUGR Rats

【目的】了解宫内发育迟缓(IUGR)和生后早期蛋白质营养不良对IUGR大鼠糖耐量和胰岛素敏感指数(ISI)及胰岛素抵抗指数(IRI)的远期影响。【方法】采用被动吸烟法制作IUGR大鼠动物模型,新生正常鼠仔102只和IUGR鼠仔105只随机分为4组:①正常对照组;②IUGR模型组;③正常大鼠低蛋白饮食组(CLP组);④IUGR大鼠低蛋白饮食组(SLP组)。观察各组大鼠在生后4周(幼年期)、12周(成年期)和48周龄(老年期)时糖耐量和胰岛素释放试验变化。【结果】①SLP组大鼠宫内发育迟缓和生后早期蛋白质营养不良其远期葡萄糖-胰岛素代谢功能受损明显,至48周时空腹血糖(5.2±1.4)mmol/L已升高,胰岛素(31. 2±3.4)mU/L水平明显升高,ISI(1.7±0.4)明显下降,IRI(8.7±1.8)明显升高,与正常对照组[(4.5±1.1)mmol/L,(12.9±1.0)mU/L和2.8±0.2,2.3±0.41比较均有显著性差异(P<0.05或P<0.01)。②CLP组大鼠生后早期单纯蛋白质营养不良的远期影响主要表现为糖负荷后胰岛素对血糖升高的应答分泌反应延迟和糖耐量减低。③IUGR模型组大鼠生后即给予正常营养供给,其葡萄糖-胰岛素代谢紊乱的程度减轻,但仍有糖耐量减低。【结论】在宫内和/或生后早期机体发育的关键时期,蛋白质营养不良将对葡萄糖-胰岛素代谢功能产生长期的不良影响。

[ Objective ] To investigate the long-term effects of postnatal protein-malnutrition on glucose tolerance and insulin sensitive index(ISI) and insulin resistance index(IRI) of IUGR rats. [Methods] IUGR models were established by passive smoking. Normal new born pups 102 and IUGR new born pups 105 were randomly divided into 4 groups: (1) The normal control group fed with normal-protein diet; (2) The IUGR control group fed with normal-protein diet; (3) The normal control group fed with low-protein diet (CLP); (4) The IUGR group fed with low-protein diet (SLP). Glucose tolerance test and insulin releasing test were performed at the 4th week (childhood), 12th week (adulth ood), 48th week (senectitude) of life in all groups. [Results] (1) Glucose-insulin metabolism in SLP group was impaired, which might be caused by IUGR and postnatal protein-malnutrition in early life afterbirth. At 48th week, the fasting plasma glucose concentration (5. 2 ± 1.4) mmol/L, insulin concentration (31. 2 ±3. 4) mU/L were both increased. ISI (1. 7 ±0. 4)decreased while IRl(8. 7 ± 1. 8)in-creased. There was significant difference compared with normal control group[ (4. 5 ± 1. 1) mmol/L, (12. 9±1.0) mU/L, 2. 8±0. 2 and 2. 3 ±0.4] respectively, P < 0. 05 or 0.01.(2)Glucose-insulin metabolism in CLP group was also damaged by protein-malnutrition in early life after birth. It mainly displayed an impaired glucose tolerance and delayed secretion of insulin response to glucose loading. (3) The damage of glucose-insulin metabolism in IUGR control group was reduced by feeding with a normal diet after birth, but impaired glucose tolerance still existed. [Conclusion] IUGR and/or protein-malnutrition at critical stage after birth will have a long-term effect on glucose-insulin metabolism, predominantly appeared as impaired glucose tolerance and/or insulin resistance.