标题：Effect of Carboxyl-Group of D-Glutamic Acid or γ-Carboxy-D-glutamic Acid as N-Terminal Amino Acid of 111In-Diethylenetriaminepentaacetic Acid-Octreotide on Accumulation of Radioactivity in Kidney
摘要：To establish a strategy for developing 111In-diethylenetriaminepentaacetic acid (111In-DTPA)-octreotide, a diagnostic radiopharmaceutical agent for tumors, with reduced non-specific renal radio-accumulation, the compounds having D -glutamic acid (Glu) or γ-carboxy- D -glutamic acid (carboxy-Glu) as the N-terminal amino acid were examined for in vivo radio-distribution. Compounds carrying Glu and carboxy-Glu containing one and two negative charges, respectively, showed lower renal radio-accumulation than that carrying D -phenylalanine. It was revealed that the introduction of a negative charge reduces the renal radio-accumulation independently from the number of negative charges. The present result can be a clue for the development of 111In-DTPA-octreotides with reduced the renal radio-accumulation.
