间歇性饥饿对亚硝酸钠所致大鼠海马神经细丝过度磷酸化及空间学习记忆损伤的改善作用

目的探讨间歇性饥饿对亚硝酸钠诱导的大鼠海马神经细丝(NF)过度磷酸化及空间学习记忆的影响。方法 36只大鼠随机分为对照组、亚硝酸钠组、饥饿+亚硝酸钠组,每组12只。亚硝酸钠组大鼠饮亚硝酸钠水水中溶入亚硝酸钠粉剂100 mg/(kg·d)],正常喂食;饥饿+亚硝酸钠组大鼠饮亚硝酸钠水,采取饥饿2d,恢复喂食3d的喂食方法,喂养60 d后通过Morris水迷宫实验检测各组大鼠的空间学习记忆能力,免疫印迹和免疫组织化学方法检测大鼠海马NF磷酸化水平与分布。结果与对照组相比,亚硝酸钠组大鼠第2天至第7天的潜伏期(53.34±5.28)s,(35.15±10.29)s,(23.52±9.50)s,(14.49±8.70)s,(16.87±8.77)s,(12.31±7.12)s]明显大于对照组(31.24±8.53)s,(12.41±6.54)s,(10.49±6.43)s,(8.61±2.56)s,(7.25±2.12)s,(6.03±1.92)s](P0.01或P0.05),跨越平台的次数(1.18±0.82)明显小于对照组(3.96±0.54,P0.05);饥饿+亚硝酸钠组只有大鼠第2天至第3天的潜伏期(43.61±1.76)s,(25.25±7.49)s]大于对照组(P0.05),第4天至第7天的潜伏期(19.47±8.30)s,(10.77±6.28)s,(12.05±7.49)s,(10.29±7.52)s]与对照组相比差异无统计学意义(P0.05)。免疫印迹和免疫组织化学结果显示,亚硝酸钠导致海马NF的磷酸化水平升高,而饥饿+亚硝酸钠组与对照组相比无明显变化。结论饥饿处理可改善亚硝酸钠导致的大鼠海马神经细丝过度磷酸化及空间学习记忆损伤。

Intermittent starvation attenuating neurofilament phosphorylation and spatial learning and memory disorder induced by sodium nitrite in rats

Objective To explore the effect of intermittent starvation on neurofilament phosphorylation and spatial learning and memory in rats induced by sodium nitrite. Methods Thirty-six rats were randomly divided into control, NaNO₂ and stavation+NaNO₂ groups, 12 rats in each group. NaNO₂ group and stavation+NaNO₂ group rats were served as drinking water containing sodium nitrite ［100mg/(kg·d)］. Starvation+NaNO₂ group rats were deprived of food for 2 days, and then re-feeded for 3 days. Sixty days later, the ability of spatial learning and memory of the rats was measured by Morris water maze. Phosphorylation level of neurofilament in the hippocampus was detected by immunohistochemistry and Western blotting. Results In comparison with the control rats, the NaNO₂ rats showed significantly longer latency to find the hidden platform from 2 days to 7 days in Morris water maze (control group latency: 31.24±8.53，12.41±6.54，10.49±6.43，8.61±2.56，7.25±2.12，6.03±1.92; NaNO₂ group latency: 53.34±5.28，35.15±10.29，23.52±9.50，14.49±8.70，16.87±8.77，12.31±7.12) (P<0.05,P<0.01), and elevated phosphorylation level of neurofilament, while stavation+NaNO₂ group rats only showed longer latency on 2 days and 3 days（43.61±1.76，25.25±7.49）in Morris water maze. There was no obvious difference in phosphorylation level of neurofilament between the control and stavation+NaNO₂ group. Conclusion Intermittent starvation attenuates neurofilament phosphorylation and spatial learning and memory disorder induced by sodium nitrite in rats.