CLINICAL-EVALUATION OF TC-99M DIAMINOCYCLOHEXANE, A RENAL TUBULAR AGENT WITH CATIONIC TRANSPORT - RESULTS IN HEALTHY-HUMAN VOLUNTEERS

As alternatives to anionically transported hippuran, structure distrib ution experiments on a series of Tc-99m-labelled primary substituted e thylene diamine compounds led to selection of Tc-99m diaminocyclohexan e (DACH) for clinical evaluation, Tc-99m DACH, a cation with the struc ture trans-[O2(DACH)2 Tc-99m]+ is prepared by mixing 50 mumol DACH, 1 mumol stannous tartarate and 500 MBq of Tc-99m. Seven normal volunteer s underwent renal imaging and clearance studies using 150 MBq of Tc-99 m DACH and 1 MBq of I-125 hippuran simultaneously. The images with Tc- 99m DACH revealed good uptake and excretion. The mean +/- 2 SD values of parenchymal and whole-kidney transit time indices and mean parenchy mal transit time were 46 +/- 33, 75 +/- 64 and 141 +/- 51 s, respectiv ely, similar to mercaptoacetyl triglycine. The mean clearance of Tc-99 m DACH was found to be 163 ml/min (SD = 32). Following cationic blocka de with 900 mg oral thiamine, significant reduction (p<0.001) in DACH clearance was noted, but hippuran clearance remained unaltered. The re sults support the hypothesis that Tc-99m DACH is transported cationica lly.