用在体脑微透析技术研究大鼠纹状体中单胺递质的释放和代谢

An in vivo study of monoamine transmitter release and metabolism in rat striatum by intracerebral microdialvsis

采用脑微透析技术与高效液相色谱-电化学检测器联用测定了清醒自由活动大鼠纹状体细胞外液中多巴胺(DA)及其酸性代谢物3,4-二羟苯乙酸(DOPAC)和高香草酸(HVA)以及5-羟色胺代谢物5-羟吲哚乙酸(5-HIAA)的含量.透析液中DA为0.44 pmol/40μl,DOPAC和HVA含量较DA高约80倍.右旋苯丙胺2 mg/kg,ip使纹状体DA释放显著增加,DOPAC和HVA含量明显下降.

A novel in vivo dialysis technique for determination of endogenous neurotransmitters and their metabolites was studied.The dialysis tube was in sorted transversally through striatum and perfused with Ringer solution.Extracellular dopamine(DA),3,4-dihydroxyphenylacetic acid(DOPAC)and homovanillic acid(HVA),as well as serotonin'smetabolite 5-hydroxyindole-3-acetic acid(5-HIAA),in striatum of the freely moving rat were measured directly by HPLC coupled with electrochemical detection.The level of DA in the striatal dialysates was found to be 0.44 pmol/40μl,while DOPAC and HVA were about 80 times more than that of DA.There was a marked increase of DA release and the simultaneous decrease of DOPAC and HVA after d-amphetamine(2mg/kg,ip)treatment.The mechanism of d-amphetamine on the dopaminergic system was discussed.The study provides a very useful and reliable in vivo system to determine endogenous substances in extracellular fluid of the freely moving animals.