Binding of tritiated and radioiodinated ZM241,385 to brain A2A adenosine receptors.
Autoradiography on rat brain using tritiated (1*), mono- (2*) and di-radioiodinated (3*) derivatives of the A(2A) adenosine receptor antagonist ZM241,385 showed high receptor density in striatum. K(D)s of 1*, 2* and 3* were 0.4, 2.2 and 15 nM and nonspecific binding was 5, 40 and 50% of total binding. Striatal uptake of 2* in mice was approximately 0.2% ID/g 60 min post-injection; blocking by 2 was insignificant. Poor penetration of the blood brain barrier and high nonspecific binding make 2* unsuitable for imaging striatal receptors.
Sihver
W
W
Institut für Nuklearchemie, Forschungszentrum Jülich GmbH, 52425 Juelich, Germany. w.sihver@fz-juelich.de
Bier
D
D
Holschbach
M H
MH
Schulze
A
A
Wutz
W
W
Olsson
R A
RA
Coenen
H H
HH
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D007553:Isotope Labeling / Q000379:methods; D008657:Metabolic Clearance Rate; D009928:Organ Specificity; D011485:Protein Binding; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D043705:Receptor, Adenosine A2A / Q000378:metabolism*; D014018:Tissue Distribution; D014227:Triazines / Q000493:pharmacokinetics*; D014230:Triazoles / Q000493:pharmacokinetics*; D014316:Tritium / Q000493:pharmacokinetics
D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D043705:Receptor, Adenosine A2A; D014227:Triazines; D014230:Triazoles; C097270:ZM 241385; D014316:Tritium