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Brain Uptake and Plasma Metabolism of [ 11 C]Vinpocetine: A Preliminary PET Study in a Cynomolgus Monkey
Author(s) -
Gulyás Balázs,
Halldin Christer,
Karlsson Per,
Chou Yuan-H.,
Swahn Cari-Gunnar,
Bönöck Peter,
Paróczai Margit,
Farde Lars
Publication year - 1999
Publication title -
journal of neuroimaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.822
H-Index - 64
eISSN - 1552-6569
pISSN - 1051-2284
DOI - 10.1111/jon199994217
Subject(s) - vinpocetine , medicine , pharmacology , pharmacokinetics , positron emission tomography , high performance liquid chromatography , distribution (mathematics) , central nervous system , basal ganglia , anesthesia , nuclear medicine , chromatography , chemistry , mathematical analysis , mathematics
Vinpocetine, a vinca alkaloid, is a widely used therapeutic agent in patients with acute and chronic stroke. To reveal the mechanisms of vinpocetine action in the brain, vinpocetine was labeled with 11 C. Positron emission tomography (PET) was used to determine the uptake and distribution of [ 11 C]vinpocetine in brain regions and the trunk of a cynomolgous monkey in two independent measurements. The concentration of vinpocetine and its labeled metabolites was determined in blood and plasma using high‐performance liquid chromatography (HPLC). Almost identical measurements were obtained in the two independent studies. After intravenous administration, following an initial peak, the total concentration of radioactivity in blood was relatively stable with time, whereas the concentration of the unchanged compound decreased with time in an exponential manner. The uptake of [ 11 C]vinpocetine in brain was rapid, and 5% of the radioactivity totally injected was present in the brain 2 minutes after drug administration, indicating that the compound entered the brain readily. The radioactivity uptake was heterogeneously distributed among brain regions and was highest in the thalamus, the basal ganglia, and certain neocortical regions. The high brain uptake and the heterogeneous regional distribution indicate that direct central nervous system (CNS) effects of vinpocetine must be considered as explanation for the therapeutic effects. The detailed exploration of this suggestion requires further studies.