MPTP对C57小鼠纹状体DA释放节律的影响

目的观察MPTP(1-甲基-4-苯基-1,2,3,6-四氢吡啶)对C57BL/6J小鼠纹状体DA(多巴胺)、5-HT(5-羟色胺)等神经递质的释放节律性的影响。方法取120只SPF级C57BL/6 J小鼠,随机分为2组:MPTP组连续5 d腹腔注射MPTP-HCl 36mg/(kg.d),对照组注射生理盐水300μL。5 d后24 h内分6个时间点:ZT0、ZT4、ZT8、ZT12、ZT16、ZT20,取纹状体,用HPLC-ECD法检测各时间点2组纹状体中DA、5-HT的水平。结果MPTP组纹状体DA水平明显降低(P<0.05);对照组DA高峰出现在ZT0(即8:30 am),低谷在ZT16(即1:30 am),MPTP组DA的高峰和低谷出现的时相未发生改变。2组5-HT均无明显节律性释放。结论小鼠纹状体的DA水平呈节律性变化,5-HT无节律性变化,MPTP作用后对DA的节律性变化无影响。表明此模型纹状体DA的减少与DA释放节律性之间不存在必然联系。

Effect of MPTP on the Circadian Oscillation of Striatal Dopamine Release in C57BL/6J

Objective To investigate the effect of MPTP on the circadian oscillation of striatal dopamine(DA) release in C57BL/6J mice.Methods 120 C57BL/6J male mice were divided into 2 groups: MPTP group was administrated with 36 mg/(kg·d) MPTP-HCl for 5 consecutive days.Control group was treated with saline.After last injection,mice were sacrificed at six different time points during the 24 h period.The DA and serotonin(5-HT) levels in the striatum were determined by HPLC with electrochemical detection.Results DA level decreased significantly in MPTP group(P<0.05).The changes of DA levels in striatum of control mice during the 24 h period revealed a significant lower point at ZT16(1:30 am) and a peak at ZT0(8:30 am).MPTP group showed the same circadian oscillation.There was no circadian oscillation of 5-HT levels in both groups.Conclusion MPTP did not affect the circadian oscillation of DA release,indicating the lack of interaction between DA decrease and circadian oscillation of DA release.