title: Technetium-99m labeled renal function and imaging agents: I. Clinical evaluation of 99mTc CO2-DADS-A (99mTc N,N'-bis-(mercaptoacetyl)-2,3-diaminopropanoate).
abstract: Animal experiments and preliminary clinical results showed that the N2S2-complex 99mTc CO2-DADS-A, which was claimed to be a potential replacement for o-I-hippurate as a renal function agent, had a lower affinity for the tubular transport system than o-I-hippurate. In order to evaluate if this finding offered the possibility of detecting decreases in tubular function with more sensitivity, or at earlier times, 6 patients in the early post-transplantation period were subjected to 53 simultaneous scintigraphic investigations with 131I o-I-hippurate and 99mTc CO2-DADS-A. The comparison of the renograms obtained with the respective agents showed that in almost all cases of acute graft rejection only o-I-hippurate yielded the typical, diagnostically useful accumulation curve which results from its high retention in the kidney parenchyma. 99mTc CO2-DADS-A did not reveal this effect. Additionally the plasma clearance of each agent was measured simultaneously under steady state conditions in nine patients. Although it was reported that relative to o-I-hippurate the analog images obtained with 99mTc CO2-DADS-A gave higher kidney-to-background ratios and the amount excreted in the urine at 30 min was slightly less, the clearance values obtained for 99mTc CO2-DADS-A were on average only 36% of those for o-I-hippurate. It is concluded that 99mTc CO2-DADS-A is not suitable as a substitute for o-I-hippurate.
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives*; D003404:Creatinine / Q000097:blood; D005069:Evaluation Studies as Topic; D006801:Humans; D007465:Iodohippuric Acid / Q000493:pharmacokinetics; D007668:Kidney / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016030:Kidney Transplantation; D007684:Kidney Tubules / Q000503:physiopathology; D008657:Metabolic Clearance Rate; D009942:Organometallic Compounds / Q000493:pharmacokinetics; D015609:Organotechnetium Compounds; D004369:Pentetic Acid / Q000097:blood; D010477:Perfusion; D011877:Radionuclide Imaging; D013667:Technetium / Q000493:pharmacokinetics; D015091:beta-Alanine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
chemical_list: D009942:Organometallic Compounds; D015609:Organotechnetium Compounds; C034974:technetium Tc-99m N,N'-bis(mercaptoacetyl)-2,3-diaminopropanoate; D015091:beta-Alanine; D007465:Iodohippuric Acid; D013667:Technetium; D004369:Pentetic Acid; D003404:Creatinine; D000409:Alanine