Technetium-99m p-iodophenethyldiaminodithiol (DADT-IPE): potential brain perfusion imaging agent for SPECT.
A new ligand, an N-p-iodophenethyl diaminodithiol (DADT-IPE), an anlog of N-isopropyl-p-iodoamphetamine (IMP), was synthesized and subsequently complexed with 99mTc, using stannous chloride as a reducing agent. Two complexes (a and b) were separated from 99mTc-DADT-IPE by high performance liquid chromatography (HPLC). Competitive inhibition studies showed that the IC50 value of DADT-IPE (70 microM) was similar to that of IMP (49 microM). Biodistribution studies of one of the complexes [99mTc-DADT-IPE(a)] in rats showed that 0.65% of the injected dose of the tracer remained in the brain at 5 min after intravenous injection, with 0.53% of the dose remaining in the brain at 60 min post-injection, whereas the corresponding values for the other complex [99mTc-DADT-IPE(b)] were 0.34% dose in the brain at 5 min and 0.28% dose in the brain at 60 min post-injection. The half-life for clearance of 99mTc-DADT-IPE(a) from rat brain was found to be more than 5 h. These results suggested that 99mTc-DADT-IPE(a) has characteristics which are suitable for cerebral perfusion imaging.
Shiba
K
K
Radioisotope Center, School of Medicine, Kanazawa University, Japan.
Mori
H
H
Matsuda
H
H
Hisada
K
K
D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D007291:Inosine Monophosphate / Q000737:chemistry / Q000378:metabolism; D007553:Isotope Labeling / Q000379:methods; D007700:Kinetics; D008297:Male; D015609:Organotechnetium Compounds / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D010477:Perfusion; D011877:Radionuclide Imaging; D051381:Rats; D011919:Rats, Inbred Strains; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D014018:Tissue Distribution
D015609:Organotechnetium Compounds; D013438:Sulfhydryl Compounds; D007291:Inosine Monophosphate; C075717:technetium Tc 99m 4-iodophenethyldiaminodithiol