Influence of paraquat on dopaminergic transporter in the rat brain.
Selective toxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a parkinsonism inducing compound, is well known to be related to an uptake of its active metabolite MPP+ into dopaminergic neurons by dopamine transporter (DAT). The aim of the present study was to examine whether paraquat, a commonly used herbicide, which is an 1-methyl-4-phenyl-pyridinium ion (MPP+) analogue, affects DAT in vivo in rats. Paraquat administered at a dose of 10 mg/kg ip decreased the binding of [3H]GBR 12,935 to DAT measured by quantitative autoradiography in the dorsal and ventral caudate-putamen, but not in the substantia nigra pars compacta. Moreover, this compound increased the level of 3-methoxytyramine (3-MT) and 3-MT/dopamine ratio in the anterior and posterior caudate-putamen measured by HPLC with electrochemical detection. No other alterations in the levels of dopamine and its metabolites were found in the caudate-putamen and substantia nigra. The present study seems to suggest that systemic paraquat administration affects striatal DAT and dopamine metabolism in the nigrostriatal neurons in rats which may be crucial for its neurotoxic effects on dopaminergic neurons.
Department of Neuro-Psychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, PL 31-343 Kraków, Poland. ossowska@if-pan.krakow.pl
Krystyna
K
Ossowska
Jadwiga
J
Wardas
Katarzyna
K
Kuter
Przemysław
P
Nowak
Joanna
J
Dabrowska
Aleksandra
A
Bortel
Łukasz
Ł
Labus
Adam
A
Kwieciński
Anna
A
Krygowska-Wajs
Stainsław
S
Wolfarth
D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D004298:Dopamine / Q000031:analogs & derivatives / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins / Q000187:drug effects* / Q000378:metabolism; D006540:Herbicides / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010269:Paraquat / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013378:Substantia Nigra / Q000187:drug effects / Q000473:pathology
D050483:Dopamine Plasma Membrane Transport Proteins; D006540:Herbicides; C001746:3-methoxytyramine; D010269:Paraquat; D004298:Dopamine