Characterization of 123I-iodo-α-methyltyrosine transport in rat lymphoma cells

123I-Iodo-α-methyltyrosine (IMT) transport into lymphomas has not been fully characterized. In rat Nb2-11C and Nb2-Sp lymphoma cell lines, linear uptake of 123I-IMT occurred rapidly within 5-10 min. Eadie-Hoftee plots of 123I-IMT uptake gave apparent Km's of 8.34±1.17 and 9.64±1.05 μM for Nb2-11C and Nb2-Sp cells, respectively, and involved the L and B0,+ systems. In lymphoma-bearing rats, injected 123I-IMT accumulated rapidly in the primary tumors but gave a low tumor-to-background ratio of 2:1. 123I-IMT was transported rapidly into lymphoma cells both in vitro and in vivo, but low target-to-nontarget ratio may not make 123I-IMT practical for scanning in vivo.