Regulation of dopamine receptors by bupropion: comparison with antidepressants and CNS stimulants.
Acute treatment of rats with the antidepressant bupropion increased [3H]spiperone binding to D2 receptors in vivo. This dose- and time-dependent effect was greatest in striatum and minimal in cerebellum and pituitary. A parallel behavioral stimulation occurred in the same rats. Among 21 antidepressants and CNS stimulants tested, only those that activate dopamine (DA) transmission had similar effects: nomifensine, amineptine, methylphenidate, D-amphetamine, amfonelic acid, cocaine, benztropine and GBR 12909. Decreasing DA transmission with reserpine plus alpha-methyl-p-tyrosine prevented the action of bupropion. Finally, bupropion was inactive in vitro and ex-vivo. Therefore, we propose that bupropion and other DA-enhancing agents modify the characteristics of [3H]spiperone binding through the intervention of a dynamic regulation of the D2 receptors by the neurotransmitter itself.
Vassout
A
A
Research Department, CIBA-GEIGY Ltd., Basel, Switzerland.
Bruinink
A
A
Krauss
J
J
Waldmeier
P
P
Bischoff
S
S
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects*; D016642:Bupropion / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects; D006719:Homovanillic Acid / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D011869:Radioligand Assay; D051381:Rats; D011954:Receptors, Dopamine / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects
D000928:Antidepressive Agents; D000697:Central Nervous System Stimulants; D011954:Receptors, Dopamine; D016642:Bupropion; D006719:Homovanillic Acid