OBJECTIVETo investigate the effect of Vitamin E (VitE) on memory and brain monoaminergic neurotransmitter level in chronic episodic hypoxia (EHYP) rat.

METHODSVitE [50 IU/ (250 g.d) or 5 IU/ (250 g.d)] was given to the EHYP rat model. The memory was evaluated by the passive avoidance test and the levels of monoaminergic neurotransmitter, including norepinephrine (NE), dopamine (DA) and 5-hydroxytryptamine (5-HT), were determined in three different brain regions (including cerebral cortex, hippocampus and striatum) using high performance liquid chromatography and electrochemical detection (HPLC-ECD).

RESULTSThe performance on passive avoidance test of EHYP rats was worse than that of controlled rats (P < 0.01). 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, levels of monoaminergic neurotransmitters in different brain regions of EHYP rats decreased significantly (P < 0.05). Compared with EHYP rats, level of NE and DA in cerebral cortex and level of monoamine (NE, DA, and 5-HT) in hippocampus and striatum of low-dose treated rats were increased significantly (P < 0.05). Different with low-dose treated rats, only level of monoamine (NE, DA, and 5-HT) in striatum and level of 5-HT in hippocampus in high-dose treated rats were increased significantly (P < 0.05), as compared with the EHYP rats.

CONCLUSIONSvitE can improve memory and increase brain monoaminergic neurotransmitter of EHYP rats. Moreover, the effect of low-dose vitE is better than that of high-dose VitE.