Effect of subacute manganese feeding on serotonin metabolism in the rat.

To clarify the effect of subacute manganese feeding on serotonin and mineral metabolism, Wistar rats were separated into two groups and fed two different diets, one a normal diet and the another a manganese-supplemented diet. After three weeks on these dietary regimens, the rats on the manganese-supplemented diet manifested the following abnormalities: blood pressure was decreased; brain serotonin was decreased; L-aromatic amino acid decarboxylase activity in brain was decreased. Manganese levels in heart, lung, and kidney increased, whereas sodium, potassium, magnesium and calcium levels in the brainstem decreased.