Relationship between the effects of dexamphetamine on locomotion and on striatal [3H]GBR 12783 binding in vivo.
In mice, low doses (1-2-4 mg/kg s.c.) of dexamphetamine stimulated locomotor activity in a dose-dependent manner. Over the same range of doses the drug dose dependently inhibited the in vivo striatal binding of the dopamine uptake inhibitor, [3H]GBR 12783. At 3 mg/kg dexamphetamine, the stimulant effect and the inhibition of the striatal binding of [3H]GBR 12783 displayed a similar time course. Pretreatments that either increased (L-DOPA 200 mg/kg, benserazide 50 mg/kg i.p.) or decreased (reserpine 5 mg/kg s.c., alpha-methyl-p-tyrosine 200 mg/kg) striatal dopamine levels did not modify the inhibition by dexamphetamine of [3H]GBR 12783 binding in vivo. This suggests that the inhibition is due to a direct effect of dexamphetamine, not mediated by endogenous dopamine, and further that a unique site is responsible for the neuronal uptake of dexamphetamine and for the binding of pure dopamine uptake inhibitors.
Vaugeois
J M
JM
Unité de Neuropsychopharmacologie Expérimentale, U.R.A. 1170 du CNRS, Faculté de Médecine et de Pharmacie de Rouen, Saint Etienne du Rouvray, France.
Bonnet
J J
JJ
Costentin
J
J
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D003913:Dextroamphetamine / Q000494:pharmacology*; D004298:Dopamine / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D018492:Dopamine Antagonists; D006719:Homovanillic Acid / Q000378:metabolism; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D010879:Piperazines / Q000494:pharmacology*; D012110:Reserpine / Q000494:pharmacology
D018492:Dopamine Antagonists; D010879:Piperazines; D015102:3,4-Dihydroxyphenylacetic Acid; D007980:Levodopa; C039737:1-(2-(diphenylmethoxy)ethyl)-4-(3-phenyl-2-propenyl)piperazine; D012110:Reserpine; C001746:3-methoxytyramine; D003913:Dextroamphetamine; D004298:Dopamine; D006719:Homovanillic Acid