褪黑激素对实验性帕金森病大鼠行为及大脑多巴胺代谢的影响

Effect of melatonin on the content of forebrain Dopa and its metabolic in Parkinson′s disease rats

目的：观察褪黑激素（Melatonin）对MPTP模型大鼠行为学和前脑多巴胺及其代谢产物含量的影响，探讨褪黑激素治疗帕金森病（PD）的作用及其机制。方法：SD大鼠60只，分为空白对照组、病理对照组和用药实验组Ⅰ～Ⅲ5组。病理对照组和用药实验组注射MPTP建立PD大鼠模型，采用爬杆法和迷宫试验测量大鼠行为学和智力改变，应用高压液相电化学法测定前脑多巴胺（DA）、高香草酸（HVA）及二羟基苯乙酸（DOPAC）含量。结果：PD模型大鼠出现不同程度爬杆能力下降和智力减退，与病理对照组相比用药实验组大鼠行为学异常可部分或全部改善。病理对照组DA、HVA、DOPAC含量均较空白对照组显著降低，用药实验组DA、HVA、DOPAC含量较空白对照组低，但较病理对照组明显增加。结论：褪黑激素可能通过抗氧化应激途径，调节前脑DA神经活性及其代谢，以改善PD症状。

Objective： To study the effect of melatonin on the content of forebrain Dopa and its metabolics in Parkinson＇s disease （PD） rats. Methods： Rats were divided into 5 groups： Blank, no melatonin treated group and lmg/kg, 5mg/kg, 10mg/kg melatonin treated group（ N = 12 respectively）. The model of PD was made by intraperitoneal injection of MPTP. The pole-slide test and ＂T＂ - maze test were used to evaluate PD rat＇s movement disorder and its dsygnosia. The level of dopamine （ DA）, 3,4dihydroxy phenyl ascetical acid （ DOPAC）, and homovaniUic acid （HVA） in forebrain were detected by high performance liquid chromatography and electrochemical detection （HPLC-EC）. Results： PD rats were suffered from severe movement disability and dementia. The contents of DA, HVA, dan DOPAC of forebrain in groups treated by melatonin was significantly higher than that of the untreated, though significantly lower than blank one. Conclusion： By the ant oxidative stress activities, Melatonin may regulate nervous activity and metabolism pathways of DA to improve PD symptoms.