Characterization of 3-[123I]iodo-L-alpha-methyl tyrosine ([123I]IMT) transport into human Ewing's sarcoma cells in vitro.
3-[(123)I]Iodo-L-alpha-methyl tyrosine ([(123)I]IMT) scintigraphy of extracranial malignant tumors has been described, but little is known about the transport systems involved in [(123)I]IMT uptake into extracranial tumor cells. Here, the precise kinetics of [(123)I]IMT transport into human Ewing's sarcoma cells (VH-64) was determined. The apparent Michaelis constant was of high affinity value (K(m)=41.7+/-3.9 microM) and maximum transport velocitiy amounted to V(max)=20.7+/-0.6 nmol x mg protein(-1) x 10 min(-1). Inhibition experiments revealed the predominance of [(123)I]IMT uptake via sodium-independent system L.
Franzius
C
C
Department of Nuclear Medicine, Westfälische Wilhelms-Universität, Münster, Albert-Schweitzer-Str. 33, 48149, Münster, Germany. franziu@uni-muenster.de
Kopka
K
K
van Valen
F
F
Eckervogt
V
V
Riemann
B
B
Sciuk
J
J
Schober
O
O
D001692:Biological Transport; D001859:Bone Neoplasms; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics*; D007700:Kinetics; D008781:Methyltyrosines / Q000493:pharmacokinetics*; D012512:Sarcoma, Ewing; D014407:Tumor Cells, Cultured
D007457:Iodine Radioisotopes; D008781:Methyltyrosines; C030855:3-iodo-alpha-methyltyrosine