TY - JOUR
T1 - Optimizing an online SPE-HPLC method for analysis of (R)-[11C]1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarb oxamide [(R)-[11C]PK11195] and its metabolites in humans
AU - Greuter, Henri N.J.M.
AU - Van Ophemert, Patricia L.B.
AU - Luurtsema, Gert
AU - Van Berckel, Bart N.M.
AU - Franssen, Eric J.F.
AU - Windhorst, Bert D.
AU - Lammertsma, Adriaan A.
PY - 2005/1/1
Y1 - 2005/1/1
N2 - (R)-[11C]PK11195 is used as a positron emission tomography tracer for activated microglia in several neurological disorders. Quantification of specific binding requires a metabolite-corrected plasma input function. In this study, a high-performance liquid chromatography (HPLC) procedure with online solid phase extraction was modified for analyzing (R)-[ 11C]PK11195 plasma samples, yielding total sample recoveries of more than 98%. When applied to human studies, the use of two HPLC systems enabled analysis of up to seven plasma samples under regular conditions. Online radioactivity detection was compared with offline sample measurements of HPLC profiles. Offline measurements provided the most reliable results especially for late plasma samples. In 10 patients, an average decrease of parent compound from 94.6% at 2.5 min to 45.2% at 1 h after administration was observed.
AB - (R)-[11C]PK11195 is used as a positron emission tomography tracer for activated microglia in several neurological disorders. Quantification of specific binding requires a metabolite-corrected plasma input function. In this study, a high-performance liquid chromatography (HPLC) procedure with online solid phase extraction was modified for analyzing (R)-[ 11C]PK11195 plasma samples, yielding total sample recoveries of more than 98%. When applied to human studies, the use of two HPLC systems enabled analysis of up to seven plasma samples under regular conditions. Online radioactivity detection was compared with offline sample measurements of HPLC profiles. Offline measurements provided the most reliable results especially for late plasma samples. In 10 patients, an average decrease of parent compound from 94.6% at 2.5 min to 45.2% at 1 h after administration was observed.
KW - (R)-[ C]PK11195
KW - Benzodiazepine receptor
KW - HPLC
KW - Metabolism
KW - Positron emission tomography
UR - http://www.scopus.com/inward/record.url?scp=16844367882&partnerID=8YFLogxK
U2 - https://doi.org/10.1016/j.nucmedbio.2004.12.005
DO - https://doi.org/10.1016/j.nucmedbio.2004.12.005
M3 - Article
C2 - 15820767
SN - 0969-8051
VL - 32
SP - 307
EP - 312
JO - Nuclear medicine and biology
JF - Nuclear medicine and biology
IS - 3
ER -