An artificial amino acid radiopharmaceutical for single photon emission computed tomographic study of pancreatic amino acid transports 123I-3-iodo-alpha-methyl-L-tyrosine.
123I-3-iodo-alpha-methyl-L-tyrosine (123I-L-AMT) was selected and its characteristics on pancreas accumulation, metabolic selectivity and metabolic stability of 125I-L-AMT were studied. The studies on rat tissue slice as well as mouse biodistribution proved very high accumulation of 125I-labeled L-AMT in the pancreas, which was remarkably inhibited by the active transport inhibitor, ouabain. 125I-L-AMT does not enter into protein synthesis and general amino acid catabolism. Moreover, 125I-L-AMT was very stable against enzymatic deiodination. Thus, the above studies indicated that the 123I-labeled L-AMT was an "artificial amino acid" radiopharmaceutical to be used for the selective measurement of the membrane amino acid transport rate in the pancreas.
Kawai
K
K
Faculty of Pharmaceutical Sciences, Science University of Tokyo, Japan.
Fujibayashi
Y
Y
Yonekura
Y
Y
Konishi
J
J
Saji
H
H
Kubodera
A
A
Yokoyama
A
A
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008297:Male; D008781:Methyltyrosines; D051379:Mice; D010042:Ouabain / Q000494:pharmacology; D010179:Pancreas / Q000000981:diagnostic imaging* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon
D000596:Amino Acids; D007457:Iodine Radioisotopes; D008781:Methyltyrosines; D010042:Ouabain; C030855:3-iodo-alpha-methyltyrosine