Abstract
Monoaminergic neurons use dopa decarboxylase (DDC; aromatic-L-amino-acid carboxy-lyase, EC 4.1.1.28) to form dopamine from L-3,4-dihydroxyphenylalanine (L-dopa). We measured regional dopa decarboxylase activity in brains of six healthy volunteers with 6-[18F]fluoro-L-dopa and positron emission tomography. We calculated the enzyme activity, relative to its Km, with a kinetic model that yielded the relative rate of conversion of 6-[18F]fluoro-L-dopa to [18F]fluorodopamine. Regional values of relative dopa decarboxylase activity ranged from nil in occipital cortex to 1.9 h-1 in caudate nucleus and putamen, in agreement with values obtained in vitro.
| Original language | English |
|---|---|
| Journal | Proceedings of the National Academy of Science of the United States of America |
| Volume | 88 |
| Issue number | 7 |
| Pages (from-to) | 2721-5 |
| Number of pages | 4 |
| ISSN | 0027-8424 |
| Publication status | Published - 1991 |
| Externally published | Yes |