Neurotransmitters in Manganese Intoxication

Papavasiliou and colleagues demonstrated an intracellular increase in the concentration of manganese in liver tissue after the administrations of DA, L-epinephrine, or DL-isoproterenol. It was also observed that this effect was mediated through an intracellular increase in cyclic 3, 5 -adenosine monophosphate. Although the importance of these studies in relation to manganese encephalopathy could not be evaluated, it became clear that a correlation existed between manganese metabolism and biogenic amines. 

Changes in the concentration of various neurotransmitters in the brain of chronically exposed animals led the investigators to study the effect of manganese on various enzymes involved in the metabolism of biogenic amines. Rats treated with MnCl2-4H20 (8 mg/kg/d) intraperitoneally for a period of 120 d showed a significant reduction in the activity of acetylcholine esterase in cere- 

Effects of Manganese Exposure on Biogenic Amines in the Central Nervous System of Animals 

References Species Manganese administration Region of brain Effects observed 

Neff et al7 Squirrel monkeys 200 mg Mn02 subcutaneously at monthly intervals Caudate nucleus Dopamine and serotonin depletion, 2 months after exposure 

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