Development of glycoside-bound radiopharmaceuticals: novel radioiodination method for digoxin.
We combined 2-hydroxy-3-methylbenzoylhydrazide (HMBH) with glycosides as a novel method for the radioiodination of physiologically active glycosides. This method was tested using digoxin, which is one of the cardiac glycosides. A digoxin-HMBH conjugate was synthesized by periodate cleavage of the third sugar ring, and was readily radiolabeled with Na[125I] by the chloramine-T method. 125I labelled digoxin-HMBH conjugate retained Na+, K(+)-ATPase binding in vivo and in vitro, and also retained immunoreactivity to an anti-digoxin antibody. Thus, this 125I labelled digoxin-HMBH conjugate represents a potential radiopharmaceutical for Na+, K(+)-ATPase imaging, as well as for the radioimmunoassay of digoxin.
Takemura
Y
Y
Department of Radiopharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
Fujibayashi
Y
Y
Dote
N
N
Taniuchi
H
H
Iijima
N
N
Konishi
J
J
Yokoyama
A
A
D000818:Animals; D000918:Antibody Specificity; D002700:Chloramines / Q000737:chemistry; D004077:Digoxin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D006168:Guinea Pigs; D007457:Iodine Radioisotopes; D007553:Isotope Labeling; D009206:Myocardium / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D011863:Radioimmunoassay; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D002700:Chloramines; D007457:Iodine Radioisotopes; C086700:digoxin-di-(2-hydroxy-3-methylbenzoylhydrazide) conjugate; D010042:Ouabain; D004077:Digoxin; D000254:Sodium-Potassium-Exchanging ATPase; C030816:chloramine