Displacement Study of 123I-2-Iodo-l-Phenylalanine Activity in Tumor Using Planar γ-Scintigraphy
| Amino acid | Contribution of transport systems (%) | %P* | %D† |
|---|---|---|---|
| l-Phenylalanine | L (70), ASC (25), O (5) | 72 | 12.3 ± 4.2 |
| l-Methionine | L (50), ASC (20), A (10), O (20) | 80 | 16.0 ± 4.2 |
| l-Cysteine | L (30), ASC (55), A (10), O (5) | 57 | 11.5 ± 7.8 |
↵* Percentage of all animals in which significant displacement of radioactivity was observed (n = 25).
↵† Percentage of tracer decrease by administering the amino acid (mean ± SD).
L = L-type transporter system; ASC = alanine, serine, and cysteine–type transporter system; O = other transporter systems; A = A-type transporter system.