Dopamine action and disorders of neurotransmitter balance.
Disorders of neurotransmitter balance are observed in Parkinson's disease, pharmacotoxic psychosis and depression. The dopamine-serotonin ratio is reduced to about 20% in Parkinson and pharmacotoxic patients in the caudate nucleus and in the substantia nigra. The serotonin content in these brain areas is lowered only to about 50% in comparison to that of the control, whereas the dopamine level is reduced to 85% in Parkinson patients. This dopamine deficiency has been substituted by exogenous supply of L-dopa in combination with decarboxylase and monoaminooxydase inhibitors. First evidence is presented that L-dopa can be replaced, at least partially, by iron in form of a ferriascorbate complex. This iron compound improves the symptoms of Parkinson's disease to almost the same extent as L-dopa.