1-Methyl-4-phenylpyridinium uptake by human and rat striatal synaptosomes.
1-Methyl-4-phenylpyridinium (MPP+) was taken up into human and rat striatal synaptosomes by a saturable system, similar to that for dopamine, with Km values of 0.24 and 0.17 microM, respectively, and similar Vmax values. Uptake of MPP+ and dopamine into both rat and human synaptosomes was inhibited by cocaine and amfonelic acid, with the latter being five to 10 times more potent than the former. MPP+ uptake was potently inhibited by dopamine in preparations from both species. In general, the characteristics of human and rat synaptosomal MPP+ uptake were very similar It seems unlikely that species differences in toxicity to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine or reaction to dopamine uptake blockers stem from this system.
Department of Chemical Pathology, Queen Charlotte's Hospital, London, England.
J
J
Willoughby
R F
RF
Cowburn
J A
JA
Hardy
V
V
Glover
M
M
Sandler
D015655:1-Methyl-4-phenylpyridinium; D000818:Animals; D003042:Cocaine / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008297:Male; D009268:Nalidixic Acid / Q000031:analogs & derivatives; D009287:Naphthyridines / Q000494:pharmacology; D011726:Pyridinium Compounds / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D009287:Naphthyridines; D011726:Pyridinium Compounds; D009268:Nalidixic Acid; D003042:Cocaine; D015655:1-Methyl-4-phenylpyridinium; C006486:amfonelic acid; D004298:Dopamine