Ligand-exchange reaction of labile "3 + 1"99mTc(V) complexes with SH group-containing proteins.
The reactivity of labile 3 + 1 mixed-ligand 99mTc complexes of the type [99mTcO(SES)(RS)] with SES being a tridentate dithiol ligand and glutathione or dimethylcysteamine as monodentate ligands RSH towards proteins was investigated in vitro and in vivo. It was found that the complexes undergo reversible transchelation reactions with SH group-containing components of blood such as albumin or haemoglobin. High labelling yields were obtained when 3 + 1 complexes with the tridentate SSS ligand were used. The biodistribution of blood proteins labelled by ligand-exchange reaction with the [99TcO(SSS)] or [99mTcO(SNMeS)] core was studied and compared with the in vivo distribution of the labile 3 + 1 complexes containing glutathione as monodentate ligand.
Institut für Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, Dresden, Germany. s.seifert@fz-rossendorf.de
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Seifert
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Gupta
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Syhre
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Spies
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Johannsen
D000818:Animals; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D008297:Male; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012709:Serum Albumin / Q000378:metabolism*; D012712:Serum Globulins / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000097:blood / Q000493:pharmacokinetics*; D013667:Technetium / Q000097:blood / Q000493:pharmacokinetics*; D014018:Tissue Distribution
D008024:Ligands; D011506:Proteins; D012709:Serum Albumin; D012712:Serum Globulins; D013438:Sulfhydryl Compounds; D013667:Technetium; D005978:Glutathione