Acute exposure to aroclor 1016 or 1260 differentially affects dopamine transporter and vesicular monoamine transporter 2 levels.

Polychlorinated biphenyls (PCBs) have been shown to specifically target the dopaminergic nervous system, resulting in long-term reduction of striatal dopamine (DA) levels. However, the mechanism(s) by which PCBs exert this effect is not known. Here we report that decreased striatal dopamine levels are observed 1, 7, and 14 days after acute exposure to the common PCB mixtures Aroclor 1016 or 1260. Dopamine transporter (DAT) levels were decreased at all time points in Aroclor 1016 treated animals, and on Days 1 and 7 in Aroclor 1260 treated animals. Vesicular monoamine transporter 2 (VMAT2) levels were not affected by Aroclor 1016, but were significantly decreased 14 days after exposure to Aroclor 1260. Tyrosine hydroxylase expression, a marker of dopamine neuron integrity, was not significantly affected by PCB exposure at any time. These data suggest that PCB-induced reductions in striatal dopamine may be mediated by alterations in DAT and VMAT2 expression.