SUBACUTE TOLUENE EXPOSURE INCREASES DA DYSFUNCTION IN THE 6-OH DOPAMINE LESIONED NIGROSTRIATAL DOPAMINERGIC SYSTEM OF THE RAT

The potential neurotoxicity of the solvent toluene to the nigrostriata l dopaminergic system was assessed in a rat model of Parkinson's disea se. Rats, 1 day after a unilateral injection of 6-hydroxydopamine (6-O H DA) into the substantia nigra, inhaled air or different concentratio ns of toluene (80, 300 or 1000 ppm), 6 h/day for 3 days. The animals w ere sacrificed 2 days after the last exposure and biochemical measurem ents of catecholamines and 3,4-dihydroxyphenylacetic acid (DOPAC) were performed in the neostriatum and substantia nigra. Toluene at 80 and 1000 ppm significantly enhanced the depletion of striatal DOPAC levels induced by the lesion and produced at 80 and 300 ppm a trend for inte nsifying the 6-OH DA-induced depletion of striatal DA stores. The alte rations induced after the combined challenge to the dopaminergic nigro striatal system may reflect endangering actions of toluene.