Basal ganglia neurotransmitter concentrations in rhesus monkeys following subchronic manganese sulfate inhalation.
BACKGROUND
Manganese neurotoxicity in humans is recognized as a form of parkinsonism with lesions occurring predominantly within the globus pallidus, subthalamic nucleus, putamen, and caudate nucleus.


METHODS
This study evaluated dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid, serotonin, norepinephrine, 5-hydroxyindoleacetic acid, gamma-aminobutyric acid (GABA), and glutamate concentrations in the globus pallidus, caudate, and putamen of male rhesus monkeys exposed subchronically to either air or manganese sulfate (MnSO4) at 0.06, 0.3, or 1.5 mg Mn/m3.


RESULTS
An approximate 1.5-6-fold increase (vs. air-exposed controls) in mean brain manganese concentration was observed following subchronic MnSO4 exposure. A marginally significant (P < 0.1) decrease in pallidal GABA and 5-hydroxyindoleacetic acid concentration and caudate norepinephrine concentration occurred in monkeys exposed to MnSO4 at 1.5 mg Mn/m3.


CONCLUSIONS
Despite the presence of increased tissue manganese concentrations, high-dose exposure to MnSO4 was associated with relatively few changes in basal ganglial neurotransmitter concentrations.
Struve
Melanie F
MF
CIIT Centers for Health Research, The Hamner Institutes for Health Sciences, Research Triangle Park, North Carolina 27709, USA. struve@ciit.org
McManus
Brian E
BE
Wong
Brian A
BA
Dorman
David C
DC
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001479:Basal Ganglia / Q000187:drug effects / Q000378:metabolism*; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D001239:Inhalation; D008253:Macaca mulatta; D017895:Manganese Compounds / Q000032:analysis; D018377:Neurotransmitter Agents / Q000032:analysis / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D020734:Parkinsonian Disorders / Q000503:physiopathology*; D012701:Serotonin / Q000378:metabolism; D013431:Sulfates / Q000032:analysis / Q000633:toxicity*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D017895:Manganese Compounds; D018377:Neurotransmitter Agents; D013431:Sulfates; D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D018698:Glutamic Acid; D006897:Hydroxyindoleacetic Acid; D005680:gamma-Aminobutyric Acid; D004298:Dopamine; C039798:manganese sulfate; D009638:Norepinephrine