Effects of chronic manganese intake on the levels of biogenic amines in rat brain regions.

After eight months of chronic manganese intake a significant decrease in the concentration of NA in striatum and pons of rats treated with 0.1 mg Mn/ml water was produced. A highly significant decrease in the levels of DOPAC was found in striatum and hypothalamus of rats receiving 0.1 and 1.0 mg Mn/ml water. HVA content diminished in the striatum of the 0.1 mg Mn/ml group. The concentration of 5-HT was reduced in midbrain of rats ingesting 1.0 mg Mn/ml water. 5-HIAA was found to be diminished in hippocampus and pons of the same group of animals and in the hippocampus of the 0.1 mg Mn/ml group. According to our findings serotonergic neurons seem to be less sensitive to manganese poisoning than catecholaminergic neurons.