Synthesis and biological characteristics of the technetium-99m triamide derivatives of mercaptoacetyltriglycine (MAG3)

A number of MAG3-derivatives, containing the three-amide functions modified by inverting the sequence -CO-NH- to -NH-CO- in the first-and/or second-amide functions, have been labelled with 99mTc in order to study the renal characteristics of the resulting MAG3-derivatives versus the reference 99mTc-MAG3. The 99mTc-MAG3-derivatives displayed HPLC-profiles similar to that of 99mTc-MAG3. Furthermore, in mice they exhibited biological behaviour comparable or even superior to 99mTc-MAG3, which indicates that the sequence of the first- and/or second-amide bond in 99mTc-MAG3 affects the biological behaviour only to a limited degree. However, in baboon the plasma clearance of the 99mTc-MAG3-derivatives was relatively slower than 99mTc-MAG3, which underlines the inter-species variability. Copyright © 2002 John Wiley & Sons, Ltd.