title: Dose-response relationship between cumulative mercury exposure index and specific uptake ratio in the striatum on Tc-99m TRODAT SPECT.
abstract: OBJECTIVE
  Tc-99m TRODAT is an agent for dopamine transporters and measuring dopamine innervation of the striatum. An association between Parkinson disease and body burden mercury level has been reported in the scientific published data. The purpose of this study was to investigate the effect of mercury exposure on dopamine transporters in the striatum measured by Tc-99m TRODAT single-photon emission computed tomography (SPECT).
  
  
  METHODS
  Study subjects included 17 workers who worked in a lamp factory at risk for mercury vapor exposure and 15 age-matched healthy controls. All subjects received Tc-99m TRODAT SPECT, brain computed tomography scan, and neurologic examinations. Biologic urine mercury levels at the end of a work week were assessed for workers.
  
  
  RESULTS
  There were significant differences in specific uptake ratio (SUR) in the striatum, caudate, and putamen between mercury exposure workers and healthy controls on Tc-99m TRODAT SPECT (all P < 0.001). The results showed a significantly negative correlation between urine and cumulative mercury levels and SUR in the striatum on Tc-99m TRODAT SPECT by Pearson analysis (r = -0.501, P = 0.040; r = -0.563, P = 0.019). After adjusting for age, gender, and body mass index, cumulative mercury exposure index (Cum Hg) was demonstrated to be the statistically significant predictor for SUR in the striatum, caudate, and putamen on Tc-99m TRODAT SPECT by multiple linear regression analysis (β = -0.543, P = 0.018; β = -0.521, P = 0.033; β = -0.465, P = 0.048).
  
  
  CONCLUSIONS
  Mercury exposure has significantly negative effect on dopamine transporters in the striatum. There is dose-response relationship between cumulative mercury exposure index (Cum Hg) and SUR in the striatum on Tc-99m TRODAT brain SPECT.
authors.affiliation: Department of Nuclear Medicine, Show Chwan Memorial Hospital, Taipei, Taiwan.
authors.forename: Chun-Yi
authors.initials: CY
authors.lastname: Lin
authors.forename: Saou-Hsing
authors.initials: SH
authors.lastname: Liou
authors.forename: Chun-Ming
authors.initials: CM
authors.lastname: Hsiech
authors.forename: Ming-Chou
authors.initials: MC
authors.lastname: Ku
authors.forename: Song-Yen
authors.initials: SY
authors.lastname: Tsai
mesh_terms: D000328:Adult; D001692:Biological Transport / Q000187:drug effects; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008628:Mercury / Q000009:adverse effects* / Q000652:urine; D017072:Neostriatum / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism*; D015609:Organotechnetium Compounds; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D015609:Organotechnetium Compounds; D014326:Tropanes; C104196:technetium Tc 99m TRODAT-1; D008628:Mercury