钳夹子宫血管致宫内生长迟缓幼鼠小脑皮层神经生长因子改变的研究

Level of Nerve Growth Factor Protein in Cerebellar Cortex of Rat Pups in Intrauterine Growth Retardation Model by Clamping the Uterine Vasculature of Pregnant Rat

目的 了解宫内发育迟缓 ( IUGR)幼鼠脑发育过程中神经生长因子 ( NGF)在不同阶段的变化 ,探讨 IU GR所致脑损伤的发生机理。方法 采用钳夹孕鼠子宫血管 30分钟的方法建立 IU GR幼鼠动物模型 ,用免疫组化染色检测 IUGR幼鼠出生时及生后第 6天小脑皮层 NGF蛋白变化。结果 1IUGR幼鼠出生体重较正常对照组降低 16 .1% (小于 2个标准差 ,P<0 .0 0 0 1) ;2 IU GR幼鼠出生时脑重较正常对照组脑重降低 ( P<0 .0 5 ) ;3IU GR幼鼠生后第 6天体重与正常对照组无差异 ( P>0 .0 5 ) ,但脑重仍有差异 ( P<0 .0 5 ) ;4IU GR幼鼠出生时小脑皮层 NGF蛋白较正常对照组降低 ( P<0 .0 0 5 ) ,且在生后第 6天仍有差异 ( P<0 .0 5 ) ,此改变与脑重改变一致。结论 本方法成功建立了 IU GR动物模型 ,且该模型所致 IUGR幼鼠伴有脑发育迟缓。IU GR幼鼠脑发育落后的发生可能与脑内 NGF水平下降有关 ,且 NGF的降低持续时间长 ,影响持久。本研究还发现 :IU GR幼鼠体格发育存在追赶生长 。

Objective To understand the level of nerve grouth fac tor(NGF) in the brain of rat pups in intrauterine growth retardation(IUGR), expl ore the mechanism of brain injury.Methods Animal models for IUG R pups were established by clamping the uteri ne vasculature of pregnant rats with 30 minutes in this study. NGF proteins were measured by immunohistochemistry in the cerebellar cortex of rat pups at birt h (21 days of gestation), and on the sixth day after birth. Results ① The body weight of the 21 day fetuses in IUGR group decreased 16.1% as compared to that in control group ( P <0.0001); ② The brain weight of the 21 day fetuses in IUGR group decreased to that in control group ( P <0 05) clevelopmen t of their brain retardation during the intrauteri ne in IUGR fetus period in this model; ③ On the sixth day after birth, there w as no statistical difference in body weight between the IUGR and the control gro ups. But the brain weight difference between these two groups was still there; ④ At birth and on the sixth day after birth, there were statistical differences in NGF proteins in cerebellu m between the IUGR and the control groups, which got along with the decrease of their brain weights.Conclusion A successful animal model of IUG R was ostablished by clamping the uterine vasculature of pregnant rats with 30 m inutes, and the development of their brain were retarded in IUGR fetus period in this model. Brain retardation in IUGR pups may relate with the decreased level of NGF in brain. This study discovered that quick “catch up” growth in physic al development and slow “catch up” growth in brain development in IUGR pups.