SIMULTANEOUS DETERMINATION OF NOREPINEPHRINE, DOPAMINE, AND SEROTONININ HIPPOCAMPAL MICRODIALYSIS SAMPLES USING NORMAL BORE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY - EFFECTS OF DOPAMINE-RECEPTOR AGONIST STIMULATION AND EUTHANASIA

A sensitive and selective conventional chromatographic method has been developed for the simultaneous measurement of norepinephrine, dopamin e, and serotonin from in vivo rat brain microdialysis samples. ion-pai r reversed-phase high performance liquid chromatography was used in co mbination with coulometric electrochemical detection to generate femto gram-level chromatograms reliably and routinely. Analysis is completed within 10 minutes making it ideally suited for the in vivo study of a cute pharmacological manipulation in the rat brain to monitor the effe cts of drugs on and the potential interactions between monoaminergic s ystems. System performance was evaluated using in vivo microdialysis p erfusate samples obtained from the right ventral hippocampus of the an esthetized rat before and after administration of the D-2/D-1 receptor agonist apomorphine as well as post-euthanasia. Basal levels and phar macological effects are reported and discussed.