Occupational exposure to PCBs reduces striatal dopamine transporter densities only in women: a beta-CIT imaging study

Abstract

We hypothesize that occupational exposure to PCBs is associated with a reduction in central dopamine (DA) similar to changes previously seen in PCB exposed adult non-human primates. To test that hypothesis, we used [(123)I]beta-CIT SPECT imaging to estimate basal ganglia DA transporter density in former capacitor workers. Women, but not men, showed an inverse relationship between lipid-adjusted total serum PCB concentrations and DA transporter densities in the absence of differences in serum PCB concentrations. These sex differences may reflect age-related reductions in the levels of gonadal hormones since these hormones have been shown experimentally to alter response to DA neurotoxicants. These findings may aid in better understanding the roles that sex and age play in modifying central DA function following exposure, not only to PCBs, but also to other DA neurotoxicants as well as further elucidating the role of gonadal hormones in influencing the initiation and/or progression of neurodegenerative disorders.

Figure 1

Dopamine transporter density measured by β-CIT SPECT imaging as a function of age by sex in former capacitor factory workers.

Figure 2

Dopamine transporter density measured by β-CIT SPECT imaging as a function of the log of current serum PCB concentrations (expressed on a lipid–adjusted basis, ppm) by sex prior to adjusting for potential confounders in former capacitor factory workers.

Figure 3

Dopamine transporter density measured by β-CIT SPECT imaging as a function of the log of current serum PCB concentrations (expressed on a lipid-adjusted basis, ppm) by sex after adjusting for age and BMI in former capacitor factory workers.