Brain-noradrenaline and 3-methoxy-4-hydroxyphenylglycol in Parkinson's syndrome.

1. Significantly reduced values of noradrenaline in Parkinson's disease were observable in all brain areas which were studied. 2. A topographic distribution of free 3-methoxy-4-hydroxyphenylglycol (MHPG) can be demonstrated in the human brain. As MHPG in the various brain areas shows a different pattern of concentration it seems that this metabolite of noradrenaline is of physiological significance and is able to reflect noradrenaline turnover. The highest values of free MHPG were found in the hypothalamus, n. accumbens, thalamus and n. ruber. 3. In a limited series of patients with Parkinson's disease post mortem analysis indicated lower values of MHPG in caudate n., putamen, s. nigra, red nucleus and n. accumbens. All other brain areas did not show significant alterations. 4. Parkinsonian patients who died during Madopar therapy demonstrated a significant increase of MHPG in caudate n., putamen, s. nigra, n. ruber, n. amygdalae and n. accumbens when compared to the untreated group, indicating an enhanced turnover of noradrenaline in these areas. 5. Bound MHPG has been estimated in various brain areas as to be in the range of 13--38 percent of free MHPG.