A reversible tracer analysis approach to the study of effective dopamine turnover.
J Cereb Blood Flow Metab
; 21(4): 469-76, 2001 Apr.
Article
em En
| MEDLINE
| ID: mdl-11323532
ABSTRACT
Changes in dopamine turnover resulting from disease states such as Parkinson's disease may be reflected in corresponding changes in the kinetics of the positron emission tomographic tracer [(18)F]fluorodopa. The authors had previously refined the conventional irreversible-tracer graphical approach to determine both the uptake rate constant K(i) and the rate constant kloss that describes the slow loss of the trapped kinetic component. Because these parameters change in the opposite sense with disease, their ratios may be more powerfully discriminating than either one alone. The ratio k(loss)/K(i) is indicative of effective dopamine turnover. Its inverse, K(i)/k(loss), can be interpreted as the effective distribution volume (EDV) of the specific uptake compartment referred to the fluorodopa concentration in plasma. Here the authors present a new approach to the estimation of EDV based on reversible-tracer graphical methods. When implemented with a plasma input function, the method evaluates EDV directly. When implemented with a tissue input function, the outcome is proportional to the ratio of the distribution volumes of the specific uptake and precursor compartments. Comparison of the new and previous approaches strongly validates this alternative approach to the study of effective dopamine turnover.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Encéfalo
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Di-Hidroxifenilalanina
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Dopamina
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Modelos Biológicos
Limite:
Animals
Idioma:
En
Revista:
J Cereb Blood Flow Metab
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Canadá