ABSTRACT
Cardiac glycosides are well known to exert a specific and powerful effect on myocardial tissue, and there is a possibility that this class of compound with a 99mTc radiolabel may behave as a superior myocardial imaging agent in comparison to 201Tl which is at present used clinically. Because of the extreme chemical complexity of cardiac glycosides a simpler aglycone, strophanthidin was selected as the pilot compound for preliminary labelling and in vivo distribution studies. Strophanthidin was converted to 19-thiosemicarbazone which nicely accommodated 99mTc to produce a pure radiopharmaceutical of high specific activity. The distribution pattern in animal models was studied which is in accordance with the metabolic studies performed earlier with the ligand itself.
