生长追赶及宫内生长迟缓对大鼠脂肪细胞增殖分化及功能的影响

摘要

目的 探讨宫内生长迟缓(IUGR)生长追赶对大鼠脂肪细胞增殖分化及功能的影响.方法 母鼠孕期饥饿法建立IUGR模型,仔鼠出生后减少每窝仔鼠数以实现生长追赶;大鼠4周时取肾周白色脂肪组织进行前脂肪细胞和成熟脂肪细胞培养并诱导分化.测定前脂肪细胞增殖能力,成熟脂肪细胞脂联素分泌水平、葡萄糖摄取率,以及各前脂肪细胞及成熟脂肪细胞的二酰基甘油酰基转移酶(DGAT)、脂蛋白脂肪酶(LPL)、胰岛素受体底物1和2(IRS1、IRS2)、磷脂酰肌醇3-激酶(P13K)mRNA表达水平.结果 IUGR大鼠前脂肪细胞的后期增殖能力高于对照组(P<0.05);IUGR大鼠成熟脂肪细胞的脂联索分泌水平低于对照组(P<0.01),葡萄糖摄取率无变化(P>0.05).IUGR大鼠前脂肪细胞,成熟细胞的DGAT、LPLmRNA表达水平高于对照组(P0.05).结论 IUGR可能在大鼠胎儿期即引起脂肪组织多基因改变,影响前脂肪细胞的增殖分化,改变成熟脂肪细胞的糖脂代谢功能,进而造成生后生长追赶者胰岛素抵抗的易感性.%Objective To investigate the expression pattern and significance of hypoxia-inducible factors la (HIF-la) and vascular endothelial growth factor (VEGF) in primary neonatal rat cortical neurons at different periods of hypoxia. Methods Primary cultured neurons were exposed to hypoxia for 0, 2, 4, 8 hours. The expressions of HIF-la and VEGF were detected by Western blot and real-time PCR. Results The HIF-la was rarely detected and the expression of VEGF was low in normoxia. The mRNA expressions of HIF-la and VEGF were significantly increased after 4 hours of hypoxia. The levels of HIF-la and VEGF peaked at 4 hours then declined to near basal level at 8 hours. Conclusions The levels of HIF-la and VEGF are increased in hypoxia. The expressions increase initially and then decline as the hypoxic time extends.