Studies of technetium-99m nitridobisdithiocarboxylate leucocyte specific radiopharmaceutical: [(TcN)-Tc-99m(DTCX)(2)], DTCX = CH3(CH2)(8)CS2. The cellular and subcellular distribution in human blood cells, and chemical behaviour. Synthesis of the analogous rhenium-188 radiopharmaceutical

The distribution of the radiopharmaceutical ([(TcN)-Tc-99m(DTCX)(2)], DTCX = CH3(CH2)(8)CS2) in the leucocyte population determinated by a density sep aration with double gradient Polymorphprep(TM) was studied. Microautoradiog raphic analysis showed a subcellular distribution of the radiomarker in hum an blood cells. This technique confirmed the observed lymphocyte selectivit y (69%) and revealed that the uptake was predominantly cytoplasmic around t he nucleus. A labeling mechanism by passive endocytosis could be proposed i nvolving a required lipophilicity of the radiopharmaceutical for lymphocyte targeting, Finally, we describe the new synthesis with an efficient yield and radiochemical purity of the analogous radiopharmaceutical [(ReN)-Re-188 (DTCX)(2)]. NUCL MED BIOL 26;2:225-231, 1999. (C) 1999 Elsevier Science Inc . All rights reserved.