The Effection Of Edaravone On Cognition Function And Expression Of GAP-43,Nogo-a In Prefrontal Cortex In Hypoxic Rats

Objectives Establishing the rat model of chronic intermittent hypoxia, to observe the learning and memory ability of rats in different groups,and detect the expression of GAP-43 and Nogo-A in the prefrontal cortex of rats. Though the study of effection and mechanism of edaravone on the hypoxic rats with cognition disfunction, in order to provide the experimental basis for curing patients with cognition disfunction causing by obstructive sleep apnea hypopnea syndrom(OSAHS).Methods 120 male wistar rats were randomly divided into three groups: NC group, 5% CIH group and ED group.The hypoxia models was made with hypoxia box(Duration of exposure time 8 h a day, 7d, 14 d, 21 d and 28 d). At 7:00 daily given in accordance with the adr injection 3 mg/Kg tail intravenous injection.the cognitive function of rats were assessed with the Morris water maze, and the changes of GAP-43 and Nogo-A in prefrontal cortex were observed by immunohistochemical. Use western blot to detect Nogo-A, gap-43 expression level. Statistical analysis Using SPSS17.0 statistical package for data analysis, the resulting data are expressed as mean ± standard deviation( x ± s), among groups were compared using one-way ANOVA(One-way ANOVA), with P<0.05 was considered statistically significant.Results 1 The effection of ED on cognitive function in rats: Rat study result: The comparation among different groups at the same time: compared with NC group, CIH group and ED group rats in 14, 21, 28 d, the escaping latency period was significantly longer(P<0.05), and comparing CIH group, ED group was less(P<0.05); Rat memory result: compared with NC group, CIH group and ED group rats in 14, 21, 28 d, the percentage of time spent on crossing the target quadrant to the total swimming time was significantly decreased(P<0.05), and comparing CIH group, ED group displayed increase(P<0.05). 2 The expression of GAP-43 and Nogo-A of prefrontal cortex in each groups by immunohistochemical: GAP-43 and Nogo-A main expressed in cytoplasm, displayed yellow or tan particles.The comparation among different groups at the same time:Compared with NC group, CIH group and ED group rats in 7、14、21、28d, the expression of GAP-43 was significantly increased(P<0.05), and comparing CIH group, ED group displayed increase(P<0.05); the expression of Nogo-A was significantly increased(P<0.05), and comparing CIH group, ED group displayed decrease(P<0.05).The comparation in different time within group: the expression of GAP-43 and Nogo-A in CIH group displayed the trend of increase, at 14 d of peak(P<0.05). 3 The expression of GAP-43 and Nogo-A of prefrontal cortex in each groups by conditional Western blot: The comparation among different groups at the same time:Compared with NC group, CIH group and ED group rats in 7、14、21、28d, the protein expression of GAP-43 was significantly increased(P<0.05), and comparing CIH group, ED group displayed increase(P <0.05); the expression of Nogo-A was significantly increased(P<0.05), and comparing CIH group, ED group displayed decrease(P<0.05); The comparation in different time within group: the expression of GAP-43 and Nogo-A in CIH group displayed the trend of increase, at 14 d of peak(P<0.05).Conclusions The mechanism of edaravone has a valid therapeutic effection on the cognitive dysfunction induced by chronic intermittent hypoxia in rats, may inhibit Oligodendrocytes Nogo-A protein and Promote neuron GAP-43 protein increases in chronic intermittent hypoxia of rats, have the effect of nerve protection, thus improve cognitive function in rats.