Bas iiis

After PET imaging using L- or D-¹⁸F-FBPA, rat was sacrificed by cervical vertebral dislocation under anesthesia, and the brain was excised and sliced at a thickness of 2 mm using a brain slicer (Muromachi Kikai). Slices were transferred to a phosphoimaging plate (BAS-IIIs, Fuji film) for 10 min of exposure with an authentic standard radioactivity source. Radioactivity was converted to digitalized imaging data using a Fuji BAS system (FLA-7000, Fuji film).

A total of 5 MBq of L- or D-¹⁸F-FBPA was injected into normal rats (n = 5/each time point) through the tail vein. Animals were killed by decapitation under isoflurane (1.5–2.0% in O₂) anesthesia 1, 5, 10, 30, 60, and 90 min after the injection; samples of the brain, heart, lung, liver, kidney, spleen, pancreas, stomach, small intestine, colon, bladder, bone, muscle, and blood were rapidly removed, and their weights and radioactivities were measured using a γ-counter (1480 WIZARD, Perkin Elmer). Standardized uptake values (SUVs) were calculated as radioactivity in tissue divided by the ratio of total injected radioactivity and body weight.
In metabolite analyses, blood samples were centrifuged to separate plasma and then weighed, and radioactivity was measured; ethanol was added to plasma (sample:ethanol = 1:1) and centrifuged, and supernatants were developed on a thin-layer chromatography (TLC) plate (TLC Silica gel 60 F254, Merck) using a mobile phase of 1-propanol/30 mM ammonium acetate/acetic acid (4/2/0.01). The TLC plate was then transferred to a phosphoimaging plate (BAS-IIIs, Fuji film) for a 10-min exposure, and radioactivity was converted to digitalized imaging data using a Fuji BAS system (FLA-7000, Fuji film). The ratio of radioactivity in the unmetabolized fraction to that in total plasma (metabolized plus unmetabolized) was calculated.