宫内发育迟缓大鼠早期追赶生长与胰岛素敏感性变化的关系

Relationship between early catch-up growth and insulin sensitivity of intrauterine growth retardation rats

目的探讨宫内发育迟缓大鼠早期追赶生长与生后胰岛素敏感性的关系。方法孕后期低蛋白限制饮食法建立宫内发育迟缓模型。分别于仔鼠生后21天、2月龄、4月龄,采用美国强生稳步型血糖仪快速测定血浆葡萄糖。采用酶联免疫吸附试验测定血清胰岛素,计算胰岛素敏感指数和胰岛素抵抗指数。结果 1)低蛋白组新生仔鼠平均出生体重为(4.37±0.69)g,低于对照组的(7.03±0.55)g,差异有统计学意义(t=-20.75,P<0.05)。低蛋白组仔鼠中宫内发育迟缓(fetal growth retardation,IUGR)的发生率为93.33%(70/75)。2)生后2月龄始,低蛋白组空腹血糖、空腹胰岛素、胰岛素抵抗指数均较对照组有所增加,胰岛素敏感性相对降低,直至4月龄,差异有统计学意义(P<0.05)。3)生后2月龄,IUGR追赶生长组空腹血糖最高,三组间空腹血糖差异均有统计学意义(P<0.05)。4)IUGR组生后7天生长速度最快,且与2月龄、4月龄胰岛素抵抗指数呈高度正相关,均具有统计学意义(P<0.05)。结论宫内发育迟缓大鼠早期追赶生长越快,成年期越容易发生胰岛素抵抗。

Objective To investigate the relationship between catch-up growth at early stage and insulin sensitivity of intrauterine growth retardation （IUGR） rat. Method An intrauterine growth retardation （IUGR） animal model was es- tablished by protein malnutrition during the mother＇s late pregnancy. Appropriate growth was defined by a weight within one SD of the colony mean,named as IUGR catch up growth group（fUGR CG）,weight which exceed the above standerd named as IUGR over catch up group （IUGR OCG）. Weight growth rate was calculated by standerd deviation score （SDS）. At 21d, 2 months and 4 months after birth,offspring rats were fasted for 12 h and then angular vein blood was collected to measure fasting plasma glucose （FPG） and fasting serum insulin level,then insulin resistance index （HOMA-IR） and insulin sensi- tivity index （ISI） were calculated. IUGR hyperglycemia group （IUGR HG） was defined by 95% limit controls of FPG. Results 1）The mean offspring birth weight of IUGR group was （4. 37±0.69）g, which was lower than that of control group （7.03±0.55）g（t=-20.75,P〈0.05）. In IUGR group, the incidence of IUGR offspring was 93.33%.2）HOMA-IR was significantIy higher in IUGR rats than that in the control group at the age of 2 months to 4 months （P〈0.05）. ISI was significantly lower at 2 months of age and continued to 4m （P〈0.05）. 3） FPG of IUGR OG was significantly higher than that of IUGR CG and control group at 2 months （P〈0.05）. 4） The growth rate of IUGR rat at 7d was the fastest,which was statistically highly correlated with insulin resistance index of 2 month and 4 month （P〈0.05）. Conclusion The more faster catch up growth at early age,the IUGR rats are more prone to have insulin resistance at adulthood.