Inhibitory effect of 4-phenyltetrahydroisoquinoline on locomotion and dopamine release induced by micro-injection of methamphetamine into the nucleus accumbens of the rat.
The inhibitory effects of 4-phenyl-1,2,3,4-tetrahydroisoquinoline (4-PTIQ) on methamphetamine-induced increases in dopamine and locomotion were investigated. Methamphetamine hydrochloride (10 micrograms) microinjected into the nucleus accumbens increased both locomotor activity and extracellular dopamine levels, measured by the brain microdialysis method. 4-PTIQ hydrochloride (20 micrograms) co-injected with methamphetamine inhibited both the increase in dopamine and the locomotor activity. The uptake blocker cocaine hydrochloride (20 micrograms) co-injected with methamphetamine failed to inhibit the effect of methamphetamine. Thus 4-PTIQ but not cocaine inhibited the dopamine-releasing effect of methamphetamine, and 4-PTIQ is suggested to block methamphetamine-induced locomotion by inhibition of dopamine release.
Tateyama
M
M
Department of Toxicology and Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
Ohta
S
S
Nagao
T
T
Hirobe
M
M
Ono
H
H
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D003042:Cocaine / Q000494:pharmacology; D003956:Dialysis; D004298:Dopamine / Q000378:metabolism*; D006719:Homovanillic Acid / Q000378:metabolism; D007546:Isoquinolines / Q000494:pharmacology*; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D044005:Tetrahydroisoquinolines
D007546:Isoquinolines; D044005:Tetrahydroisoquinolines; D015102:3,4-Dihydroxyphenylacetic Acid; D008694:Methamphetamine; C074266:4-phenyl-1,2,3,4-tetrahydroisoquinoline; D003042:Cocaine; D004298:Dopamine; D006719:Homovanillic Acid