CHEMICAL AND INVIVO STUDIES OF THE ANION OXO[N,N'-ETHYLENEBIS(2-MERCAPTOACETIMIDO)]TECHNETATE(V)

Abstract

Studies of the anionic coordination complex 99mTc-oxo[N,N''-ethylenebis(2-mercaptoacetimido)]technetate(V) ([TcO(ema)]-) are described. Syntheses performed both at carrier levels (10-5 M) and with no carrier added (< 10-8 M) indicate that the complex is formed virtually quantitatively from pertechnetate ion over this range. Tissue distributions in normal rats are similar at both concentrations up to 1 h after administration. High-pressure liquid chromatography and field-desorption mass spectrometry showed that the anion is excreted unchanged into both urine and bile. The effectiveness of this N2S2 donor set in sequestering 99mTc, and the in vivo stability of the resulting complex, suggest that modified chelates of this structural class could provide a series of useful diagnostic agents.