We propose a renal imaging agent, the Tc-99m complex of the bidentate-
N,S chelate N-(mercaptoacetyl)glycine (Tc-99m-2GAM), with the imaging
characteristics of Tc-99m-DMSA but a faster kidney uptake; chemical ev
idence supports the formulation of Tc-99m-2GAM as [Tc-V(O)(GAM)(2)](-)
. After biodistribution and toxicity studies in animals, Tc-99m-2GAM w
as evaluated in five normal volunteers. Tc-99m-2GAM is rapidly cleared
from the blood t(1/2), = 9 min) and 50% of the ID is excreted in the
urine in the first 2 h. Dynamic data show a rapid renal uptake that in
creases up to 1 h with no significant wash-out between 1 and 8 h. The
uptake in each kidney ranges from 11.3% to 20.7% ID. Low, stable liver
uptake is observed. No significant activity is detected in other orga
ns. We showed no differences between Tc-99m-2GAM and Tc-99m-DMSA compa
red in three patients with unilateral kidney disease, We conclude that
Tc-99m-2GAM has good practical and dosimetric features for renal imag
ing. Copyright (C) 1996 Elsevier Science Inc.