Neutral technetium(II)-99m complexes as potential brain perfusion imaging agents.
A series of eight neutral technetium(II)-99m complexes of general formula tr-[99mTcIID2X2]0, where D represents a chelating ditertary phosphine or arsine ligand and X represents a halide or pseudohalide ligand, has been prepared and characterized by HPLC comparisons to the known 99Tc analogs. Several members of this series exhibit significant brain uptake in rats, with maximum uptake (1.2% dose/brain at 1 min after injection) being exhibited by tr-[99mTcII (DIARS)2Cl2]0 where DIARS represents o-phenylenebis(dimethylarsine). Surprisingly, several cationic Tc(III) analogs, tr-[99mTcD2X2]+, also exhibit significant brain uptake, presumably via a mechanism which involves in vivo reduction to the neutral Tc(II) form. The complicated interrelationships among the chemical and biological properties of the tr-[99mTcIII/IID2X2]+/0 couples, and the dependencies of these properties on the nature of D and X, provide possible means by which this class of complexes might be manipulated to yield an effective 99mTc brain perfusion imaging agent.
Neves
M
M
Department of Chemistry, University of Cincinnati, OH 45221.
Libson
K
K
Deutsch
E
E
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D005260:Female; D007700:Kinetics; D011877:Radionuclide Imaging; D051381:Rats; D011919:Rats, Inbred Strains; D013329:Structure-Activity Relationship; D013667:Technetium / Q000378:metabolism
D013667:Technetium