维甲酸对宫内缺氧幼年大鼠神经干细胞增殖及学习记忆能力的影响

Effect of retinoic acid on proliferation of neural stem cells and memory and learning capacity of intrauter in hypoxia juvenile rats

【目的】探讨维甲酸对宫内缺氧幼年大鼠神经干细胞增殖及学习记忆能力的影响。【方法】孕SD大鼠制作宫内缺氧性脑损伤新生鼠模型。新生鼠随机分为对照组及维甲酸治疗组(治疗组)各10只。治疗组每只每天给予腹腔注射维甲酸500μg/kg,容积0.2 mL/次。对照组注射生理盐水0.2 mL,共10 d。30 d后进行Morris水迷宫实验,水迷宫实验结束的当天取脑组织、固定,常规石蜡切片(经海马),Nestin免疫组织化学染色神经干细胞。显微镜下观察其海马回Nestin阳性神经干细胞。【结果】治疗组大鼠海马回Nestin阳性细胞数(11.67±2.10)较对照组(4.82±0.52)明显增加(t=8.58,P<0.01);在目标象限,对照组大鼠搜索时间[(18.27±3.38)s,(10.78±2.20)s]均较治疗组[(23.12±2.16)s,(18.05±2.24)s]明显缩短(t=3.26,6.02,P均<0.01)。【结论】维甲酸可刺激宫内缺氧幼年大鼠海马神经干细胞的增殖,因此有效地改善大鼠远期的学习记忆功能。

[Objeetive] To explore the effect of retinoic acid（RA） on proliferation of neural stem eells（NSC） and memory and learning capacity of intrauter in hypoxia juvenile rats. [Methods] Conceiving female SD rats to make the injured brain newborn rats model, newborn rats were randomly divided into 2 groups：control group （n= 10） and retinoic acid treatment group （n= 10） ,and intraperitoneal injection RA （500μg/kg ）in treated group, control group in NS. The juvenile rats were taken to do the experiment of watermaze after they were born in 30 d, then killed when the experiment was over, the brains of the rats were taken, immobilization, paraffin imbedding, slicing （hippocampus）,common immunohistochemistry staining were used to detect the Nestin positive NSCs. [ Results] Nestin positive cells in hippocampus of retinoic acid treatment group （11.67± 2.10）was higher than that of control group （4.82 ± 0.52）（t = 8.58, P〈0.01 ）. Times that rats of control group spent in target quadrant [ （18.27±3.38 ） s, （ 10.78 ± 2.20） s ] were shorten than those of treatment group [（23.12±2.16）s,（18.05±2.24）s] （t=3.26,6.02,P〈0.01）. [Conclusion] Retinoic acid can induce the proliferation of neural stem cells, promoting memory and learning capacity of intrauter in hypoxia juvenile rats.