Brain mercury in neurodegenerative disorders.
BACKGROUND
Trace element neurotoxicity has long been invoked as an etiologic factor for Alzheimer's disease. This study was conducted to determine the concentrations of mercury in seven different brain regions from deceased patients histologically confirmed with Alzheimer's disease or multiple sclerosis as compared to control subjects without known central nervous system and renal disorders. Brain mercury concentrations in all deceased subjects can arise from amalgam restorations, diet, and the working environment.


METHODS
Autopsy frozen specimens (control, Alzheimer's disease and multiple sclerosis) from seven brain regions, which included frontal cortex, temporal cortex, occipital cortex, putamen, hippocampus, corona radiata and corpus callosum were assayed for the concentrations of selenium using instrumental neutron activation analysis and mercury using radiochemical neutron activation analysis.


RESULTS
We found that the concentrations of mercury and the mercury/selenium molar ratios were significantly lower in the hippocampi of multiple sclerosis patients as compared to aged-matched controls. However, no statistically significant differences were detected for the concentrations of mercury and the mercury/ selenium molar ratios for the remaining six brain regions among these groups.


CONCLUSIONS
Since brain mercury concentrations from deceased subjects with either Alzheimer's disease or multiple sclerosis are not significantly higher than controls, the present study provides no scientific support that mercury plays a significant role in the pathogenesis of these neurologic disorders.
Fung
Y K
YK
Department of Oral Biology, University of Nebraska Medical Center, College of Dentistry, Lincoln 68583-0740, USA.
Meade
A G
AG
Rack
E P
EP
Blotcky
A J
AJ
D000368:Aged; D000544:Alzheimer Disease / Q000209:etiology / Q000378:metabolism*; D001822:Body Burden; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D006801:Humans; D008628:Mercury / Q000493:pharmacokinetics*; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000209:etiology / Q000378:metabolism*; D012643:Selenium / Q000032:analysis; D014018:Tissue Distribution
D008628:Mercury; D012643:Selenium