title: High myocardial accumulation of radioiodinated digoxin derivative: a possible Na,K-ATPase imaging agent.
abstract: In view of the high binding ability of cardiac glycosides to the myocardial Na,K-ATPase, radioiodinated digoxin derivatives were surveyed as candidates for myocardial imaging, with particular emphasis on the noninvasive monitoring of cardiac glycoside therapy. Among the radioiodinated digoxin derivatives surveyed, 125I-digoxin-iodohistamine(bis(O-carboxymethyloxime)) showed the highest accumulation in the myocardium and similar binding ability to Na,K-ATPase as digoxin itself against ouabain displacement, as indicated by in vivo and in vitro studies. Based on these results, 123I labeling of digoxin-histamine(bis(O-carboxymethyloxime)) and imaging in a dog demonstrated uptake in the myocardium.
authors.affiliation: Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujibayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Takemura
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: K
authors.initials: K
authors.lastname: Wada
authors.forename: Y
authors.initials: Y
authors.lastname: Yonekura
authors.forename: J
authors.initials: J
authors.lastname: Konishi
authors.forename: A
authors.initials: A
authors.lastname: Yokoyama
mesh_terms: D000818:Animals; D004077:Digoxin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004285:Dogs; D006168:Guinea Pigs; D006321:Heart / Q000000981:diagnostic imaging*; D006632:Histamine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D007457:Iodine Radioisotopes; D008297:Male; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D011877:Radionuclide Imaging; D000254:Sodium-Potassium-Exchanging ATPase; D014018:Tissue Distribution
chemical_list: D007457:Iodine Radioisotopes; C073805:digoxin-iodohistamine(bis(O-carboxymethyloxime)); D004077:Digoxin; D006632:Histamine; D000254:Sodium-Potassium-Exchanging ATPase