A second-generation 99m technetium single photon emission computed tomography agent that provides in vivo images of the dopamine transporter in primate brain.
The dopamine transporter (DAT), located presynaptically on dopamine neurons, provides a marker for Parkinson's disease (Pd) and attention deficit hyperactivity disorder (ADHD). In ADHD, DAT density levels are elevated, while in Pd these levels are depleted. The depletion of DAT levels also corresponds with the loss of dopamine. We now describe the design, synthesis, biology, and SPECT imaging in nonhuman primates of second-generation (99m)technetium-based tropane ligands that bind potently and selectively to the DAT. We demonstrate that improved selectivity and biological stability allows sufficient agent to enter the brain and label the DAT in vivo to provide a quantitative measure of DAT density in nonhuman primates. We introduce FLUORATEC (N-[(2-((3'-N'-propyl-(1"R)-3"alpha-(4-fluorophenyl)tropane-2"beta-1-propanoyl)(2-mercaptoethyl)amino)acetyl)-2-aminoethanethiolato]technetium(V) oxide), a DAT imaging agent that has emerged from these studies and is now in phase 1 clinical trials in the U.S.
Meltzer
Peter C
PC
Organix Inc., 240 Salem Street, Woburn, MA 01801, USA. meltzer@organixinc.com
Blundell
Paul
P
Zona
Thomas
T
Yang
Lihua
L
Huang
Hong
H
Bonab
Ali A
AA
Livni
Eli
E
Fischman
Alan
A
Madras
Bertha K
BK
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D066298:In Vitro Techniques; D008024:Ligands; D008252:Macaca fascicularis; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000378:metabolism*; D009419:Nerve Tissue Proteins; D015609:Organotechnetium Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics; D011485:Protein Binding; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics; D013237:Stereoisomerism; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics
D050483:Dopamine Plasma Membrane Transport Proteins; D008024:Ligands; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; C476597:N-((2-((3'-N'-propyl-3''-(4-fluorophenyl)tropane-2'-1-propanoyl)(2-mercaptoethyl)amino)acetyl)-2-aminoethanethiolato)technetium(V) oxide; D009419:Nerve Tissue Proteins; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D014326:Tropanes; D004298:Dopamine