Modulation of [3H]mazindol binding sites in rat striatum by dopaminergic agents.
This study was undertaken to examine whether repeated alteration of dopamine turnover influences the function of dopamine uptake sites. In the first experiment, rats were repeatedly injected intraperitoneally with L-3,4-dihydroxyphenylalanine (L-DOPA), alpha-methyl-p-tyrosine or 1-[2-bis(4-fluorophenyl)methoxy]ethyl]-4-(3- phenylpropyl)piperazine (GBR 12909) once daily for 14 days. An increase in the number of [3H]mazindol binding sites in the striatum was seen with L-DOPA and GBR 12909. A decrease was seen with alpha-methyl-p-tyrosine. In the second experiment, the effect of a single treatment with the same drugs was investigated and no change in the number and affinity of [3H]mazindol binding sites was found. These results indicate that the number of dopamine uptake sites is modulated by persistent changes in dopamine turnover, and that repeated treatment with a selective dopamine uptake inhibitor, GBR 12909, increases their number.
Ikawa
K
K
Department of Neuropsychiatry, Tokyo Metropolitan Hiroo General Hospital, Japan.
Watanabe
A
A
Kaneno
S
S
Toru
M
M
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D004298:Dopamine / Q000378:metabolism; D015259:Dopamine Agents / Q000494:pharmacology*; D006719:Homovanillic Acid / Q000378:metabolism; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D008454:Mazindol / Q000378:metabolism* / Q000493:pharmacokinetics; D008781:Methyltyrosines / Q000494:pharmacology; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017661:Receptors, Presynaptic / Q000187:drug effects; D014446:Tyrosine 3-Monooxygenase / Q000037:antagonists & inhibitors; D019805:alpha-Methyltyrosine
D015259:Dopamine Agents; D008781:Methyltyrosines; D014179:Neurotransmitter Uptake Inhibitors; D010879:Piperazines; D017661:Receptors, Presynaptic; D015102:3,4-Dihydroxyphenylacetic Acid; D007980:Levodopa; D019805:alpha-Methyltyrosine; C043425:vanoxerine; D008454:Mazindol; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine; D006719:Homovanillic Acid