title: Do organic solvents induce changes in the dopaminergic system? Positron emission tomography studies of occupationally exposed subjects.
abstract: OBJECTIVE
  The objective of this study was to test the hypothesis that long-term occupational exposure to organic solvents may effect the levels and turnover of dopamine in man.
  
  
  METHODS
  A study was performed on 17 patients with neuropsychiatric symptoms due to occupational solvent exposure, and 11 healthy non-exposed male volunteers (controls). Positron emission tomography (PET) was used to assess striatal dopaminergic function, using L-[11C]DOPA, [11C]nomifensine and [11C]raclopride as tracers.
  
  
  RESULTS
  The rate of dopamine synthesis was significantly increased among subjects with occupational exposure to organic solvents compared with non-exposed controls. After controlling for the difference in age between exposed and controls, the effect of solvent exposure became less apparent and was reduced from +32% (P = 0.009) to +25% (P = 0.07). There were no differences with regard to the binding of [11C]nomifensine. Patients with and without the diagnosis of toxic encephalopathy did not differ with regard to their putaminal uptake of L-[11C]DOPA, [11C]nomifensine and [11C]raclopride.
  
  
  CONCLUSIONS
  The data support the hypothesis that long-term exposure to organic solvents may increase the rate of dopamine synthesis in the brain without affecting the number of presynaptic terminals or postsynaptic dopamine receptors.
authors.affiliation: Department of Occupational and Environmental Medicine, University Hospital, Uppsala, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Edling
authors.forename: B
authors.initials: B
authors.lastname: Hellman
authors.forename: B
authors.initials: B
authors.lastname: Arvidson
authors.forename: J
authors.initials: J
authors.lastname: Andersson
authors.forename: P
authors.initials: P
authors.lastname: Hartvig
authors.forename: A
authors.initials: A
authors.lastname: Lilja
authors.forename: S
authors.initials: S
authors.lastname: Valind
authors.forename: B
authors.initials: B
authors.lastname: Långström
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019954:Neurobehavioral Manifestations; D016273:Occupational Exposure; D009930:Organic Chemicals; D012997:Solvents; D014055:Tomography, Emission-Computed
chemical_list: D009930:Organic Chemicals; D012997:Solvents; D004298:Dopamine