维生素E对慢性间断性缺氧大鼠学习记忆的作用

Effect of VitE on learning-memory ability in chronic episodic hypoxia rat

目的 探讨不同剂量维生素E (VitaminE ,VitE)对慢性间断性缺氧 (chronicepisodichypoxia ,EHYP)大鼠学习记忆能力和脑内胆碱乙酰转移酶 (cholineacetyltransferase,ChAT)活性的影响。方法 建立EHYP大鼠模型 ,并给予大 (50IU 2 50g体重 d)、小(5IU 2 50g体重 d)剂量VitE干预。用被动避暗回避反射试验评价大鼠学习记忆能力 ,潜伏期 (STL)越长 ,学习记忆能力越强 ;用放射化学法测定大鼠皮层、海马和纹状体ChAT活性。结果 EHYP处理后 ,与对照组相比 ,EHYP组大鼠STL明显缩短 (P <0 .0 1 ) ,各脑区ChAT活性均显著降低 (P <0 .0 5)。药物干预后 ,与EHYP组相比 ,VitE大、小剂量组大鼠STL均显著延长 (VitE大剂量组 :P<0 .0 5 ,VitE小剂量组 :P <0 .0 1 ) ,但大剂量组大鼠STL明显短于小剂量组 (P <0 .0 5) ;就ChAT活性而言 ,小剂量组大鼠各脑区ChAT活性均显著升高 (P <0 .0 5) ,而大剂量组大鼠仅海马和纹状体ChAT活性显著升高 (P <0 .0 5)。结论 VitE可改善EHYP大鼠学习记忆能力并提高其脑内ChAT活性 。

Objective To investigate the effect of Vitamin E (VitE) on learning memory ability and brain choline acetyltransferase (ChAT) activity in chronic episodic hypoxia (EHYP) rat. Methods After establishing the rat model of EHYP, VitE (50IU/250g/d or 5IU/250g/d) was given to the EHYP rat. The learning memory ability was evaluated by the passive avoidance test and the ChAT activity in three different brain regions (including cerebral cortex, hippocampus and striatum) was determined using radiochemical method. Results The performance on passive avoidance test of EHYP rats was worse than that of controlled rats (P< 0.01 ). Although the performance of rats in two different treatment groups was better than that of EHYP rats (P<0.05), the performance of rats in high dose group was worse than that of rats in low dose group (P<0.05). Compared with controlled rats, ChAT activity in all different brain regions in EHYP rats decreased significantly (P<0.05). Compared with EHYP rats, ChAT activity in all different brain regions in low dose treated rats increased significantly (P<0.05) while ChAT activity only in hippocampus and striatum in high dose treated rats increased significantly (P<0.05). Conclusion VitE can improve learning memory ability and increase brain ChAT activity in EHYP rats. However, the effect of low dose VitE is better than that of high dose VitE.