title: In vivo release of endogenous dopamine, 5-hydroxytryptamine and some of their metabolites from rat caudate nucleus by phenylethylamine.
abstract: The in vivo release of endogenous 3,4-dihydroxyphenylethylamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 3-methoxytyramine (3-MT), and of 5-hydroxytryptamine (5-HT) and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), has been measured in the caudate nucleus of the anesthetized rat. A push-pull cannula was implanted into the brain, and the tissue perfused with artificial CSF or artificial CSF containing 5 X 10(-4) M phenylethylamine. The perfusate was collected and analyzed for DA, 5-HT and their metabolites by high performance liquid chromatography with electrochemical detection (HPLC-ECD). DA was released by phenylethylamine at rates significantly greater than its basal rate. 3-MT and 5-HT were undetectable in perfusates collected under basal conditions, but could be detected readily during phenylethylamine stimulation. DOPAC, HVA and 5-HIAA concentrations were not significantly affected by phenylethylamine. The results suggest (1) that phenylethylamine may exert its behavioural effects through increased release of both DA and 5-HT, and (2) that in vivo measurements of the acid metabolites alone may not be indicative of the release of the amines.
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000032:analysis; D000818:Animals; D002421:Caudate Nucleus / Q000187:drug effects* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism*; D006719:Homovanillic Acid / Q000032:analysis; D006897:Hydroxyindoleacetic Acid / Q000032:analysis; D008297:Male; D010627:Phenethylamines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*
chemical_list: D010627:Phenethylamines; D015102:3,4-Dihydroxyphenylacetic Acid; C029261:phenethylamine; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; C001746:3-methoxytyramine; D004298:Dopamine; D006719:Homovanillic Acid