Objectives: Polychlorinated biphenyls (PCBs) cause environmental chemical contamination and tend to bio-accumulate in living organisms due to their lipophylic properties. In this study, we have investigated effects two different Aroclor mixtures (Aroclor A1221 and A1254) on catecholamine levels in the cortex, striatum, hippocampus and hypothalamus in female rats.

Material and Methods: Total 25 adult female Wistar rats were divided in three groups and subcutaneously injected with vehicle alone (4% dimethyl sulphoxide), A1221 (10 mg/kg) and A1254 (10 mg/kg) every other day for a period of 46 days. At the end of the experiments, animals were decapitated and brains rapidly removed. Cortex, striatum, hippocampus and hypothalamus regions were isolated, and homogenized. Brain noradrenalin, dopamine and metabolites concentrations were determined by HPLC-ECD method.

Results: A1221 administration significantly increased levels of noradrenalin and its metabolite (dihydroxyphenyl glycol, DHPG) in cortex and striatum (p<0.05), and reduced in hypothalamus and hippocampus (p<0.05). A1254 elevated DHPG concentrations in hypothalamus and cortex, and also increased this metabolite with parent catecholamine in striatum (p<0.05). Both PCB mixtures significantly decreased dopamine levels in all of the areas (p<0.05). It reduced levels of dopamine metabolite dihydroxyphenylacetic acid in hippocampus, but caused increases in others areas (p<0.05).

Conclusion: PCBs affect noradrenergic and dopaminergic neurotransmitter levels in various brain regions. Our results implicate that PCB contamination may be of importance in terms of predisposition for neurodegenerative diseases. We suggest that in addition to general toxic effects of these compounds, their effects on the central catecholaminergic system should also be considered. ©2007, Firat University, Medical Faculty