Subchronic toluene exposure in low concentrations produces signs of reduced dysfunction in the 6-hydroxydopamine lesioned nigrostriatal dopaminergic system of the rat.
The effect of a subchronic (4-week) exposure to low concentrations of toluene (40 or 80 parts per million, ppm) on the brain dopaminergic system has been examined in a rat model of Parkinson's disease. A unilateral lesion of the substantia nigra (SN) dopamine (DA) nerve cells was performed by injection of a low dose of 6-hydroxydopamine (6-OH DA). The peak activity of contralateral rotational behavior induced by apomorphine was significantly decreased after exposure to 80 ppm toluene. Analysis of the neostriatum and SN ipsilateral to the lesion revealed that toluene (80 ppm, but not 40 ppm) counteracted the 6-OH DA-induced reductions of DA tissue levels both within the SN and the neostriatum. Also the lesion-induced reduction of immunoreactivity for tyrosine hydroxylase (TH IR) in the neostriatum was partly counteracted by the toluene exposure (80 ppm). In conclusion, a subchronic exposure to low doses of toluene (80 ppm) leads to signs of reduced dysfunction of the nigrostriatal dopaminergic system after the neurotoxic treatment.
Cintra
A
A
Department of Neuroscience, Karolinska Institutet, Solna, Sweden. antonio.cintra@mednutr.ki.se
Aguirre
J A
JA
Andbjer
B
B
Finnman
U B
UB
Hagman
M
M
Agnati
L F
LF
Höglund
C
C
Möller
A
A
Fuxe
K
K
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D003714:Denervation; D004298:Dopamine / Q000378:metabolism*; D007276:Injections, Intraventricular; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D017072:Neostriatum / Q000187:drug effects* / Q000378:metabolism; D016627:Oxidopamine / Q000633:toxicity*; D020734:Parkinsonian Disorders / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013378:Substantia Nigra / Q000187:drug effects* / Q000378:metabolism; D014050:Toluene / Q000008:administration & dosage* / Q000494:pharmacology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D015102:3,4-Dihydroxyphenylacetic Acid; D014050:Toluene; D016627:Oxidopamine; D014446:Tyrosine 3-Monooxygenase; D001058:Apomorphine; D004298:Dopamine