Evaluation of radioiodinated 8-Cyclopentyl-3-[(E)-3-iodoprop-2-en-1-yl]-1-propylxanthine ([*I]CPIPX) as a new potential A1 adenosine receptor antagonist for SPECT.
8-Cyclopentyl-3-[(E)-3-[(131)I]iodoprop-2-en-1-yl]-1-propylxanthine (2*) was generated by iododestannylation of the tributyl-stannyl-precursor with [(131)I]NaI and chloramine T. The radiochemical yield of 2* was 82 +/- 4%, and the purity exceeded 98%. The specific activity was 33 +/- 19 GBq/micromol. Affinities for rat, pig and human A(1) adenosine receptors (A(1)ARs) were in the low nanomolar range, but poor selectivity for the human A(1)AR over the A(2A)AR was found. Additionally, in vitro and ex vivo autoradiographic studies revealed high unspecific binding which makes this ligand unsuitable for SPECT imaging.
Sihver
W
W
Institute of Nuclear Chemistry, Research Center Jülich GmbH, D-52428 Jülich, Germany. w.sihver@fz-juelich.de
Holschbach
M H
MH
Bier
D
D
Wutz
W
W
Schulze
A
A
Olsson
R A
RA
Coenen
H H
HH
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D002460:Cell Line; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008657:Metabolic Clearance Rate; D051379:Mice; D009928:Organ Specificity; D058915:Purinergic P1 Receptor Antagonists; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D018047:Receptors, Purinergic P1 / Q000145:classification / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013045:Species Specificity; D013552:Swine; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D019820:Xanthine / Q000138:chemical synthesis / Q000493:pharmacokinetics*; D014970:Xanthines
C485081:8-cyclopentyl-3-(3-iodoprop-2-en-1-yl)-1-propylxanthine; D058915:Purinergic P1 Receptor Antagonists; D019275:Radiopharmaceuticals; D018047:Receptors, Purinergic P1; D014970:Xanthines; D019820:Xanthine