褪黑素对急性睡眠剥夺大鼠行为的影响及机制

目的:探讨褪黑素对急性睡眠剥夺(SD)大鼠行为的影响及可能的作用机制.方法:将Sprague Dawley 24只大鼠随机分为3组,对照组给予SD和生理盐水腹腔注射,2个实验组分别给予SD和褪黑素5 mg/kg和15 mg/kg腹腔注射,连续给药7 d后,采用小平台水环境法建立大鼠SD模型,SD 72 h用旷场反应箱测试大鼠的行为,用试剂盒检测大鼠大脑皮层和海马中一氧化氮(NO)和丙二醛(MDA)含量.结果:实验组旷场反应测试大鼠兴奋性和探索性行为均明显小于对照组(P<0.05, P<0.01),有量效关系.实验组大鼠大脑皮层和海马组织中NO和MDA含量明显低于对照组(P<0.01).结论:褪黑素对睡眠剥夺大鼠行为障碍有改善作用,这种作用可能与抑制睡眠剥夺大鼠大脑皮层和海马中NO及MDA的升高有关.

Effect of melatonin on behavior of rats of acute sleep deprivation and its working mechanism

AIM: To explore the effect of melatonin (MT) on the behavior of rats with acute sleep deprivation (SD) and the related bio-mechanism. METHODS: Twenty-four Sprague Dawley rats were divided into 3 groups: control group (SD + sodium chloride), experimental group 1 (SD + MT, 5 mg/ kg) and experimental group 2 (SD + MT, 15 mg/ kg). The rats were injected intraperitoneally with MT or sodium chloride one time a day for 1 week. SD was induced in the rats housed on small platform over water. After 72 h SD, the rats' behavior was measured by "open field test" and then malondialdehyde (MDA) and nitric oxide (NO) contents in cerebral cortex and hippocampus of the rats were measured by TBA and Griess method respectively. RESULTS: The excitability and explorative behavior of the 2 experimental groups in the "open field" significantly decreased compared with those of the control group (P<0.05, P<0.01). There was a dose-effect relationship in the experimental groups. The contents of NO or MDA in cerebral cortex and hippocampus of the experimental groups were lower than those of the control group(P<0.01). CONCLUSION: Melatonin depresses the excitability in the rats of acute sleep deprivation, possibly by inhibiting the increase of NO and MDA in cerebral cortex and hippocampus of the rats.