title: Kinetic parameters of 3-[(123)I]iodo-L-alpha-methyl tyrosine ([(123)I]IMT) transport in human GOS3 glioma cells.
abstract: The radiolabelled amino acid 3-[(123)I]iodo-L-alpha-methyl tyrosine ([(123)I]IMT) is a promising tool for the diagnosis and monitoring of brain tumors using single-photon emission tomography (SPECT). However, little is known about the precise kinetics of [(123)I]IMT uptake in human glioma cells. The kinetic analysis of [(123)I]IMT transport in human GOS3 glioma cells yielded a high-affinity apparent Michaelis constant (K(m) = 20.1 +/- 1.5 microM). The maximum transport velocity (V(max)) amounted to 34.8 +/- 1.9 nmol/mg protein/10 min. Competitive inhibition experiments revealed that [(123)I]IMT transport is mediated principally by the sodium-independent system L.
authors.affiliation: Department of Nuclear MedicineWestfälische Wilhelms-Universität, Münster, Germany. riemanb@uni-muenster.de
authors.forename: B
authors.initials: B
authors.lastname: Riemann
authors.forename: K
authors.initials: K
authors.lastname: Kopka
authors.forename: F
authors.initials: F
authors.lastname: Stögbauer
authors.forename: H
authors.initials: H
authors.lastname: Halfter
authors.forename: S
authors.initials: S
authors.lastname: Ketteler
authors.forename: T Q
authors.initials: TQ
authors.lastname: Phan
authors.forename: C
authors.initials: C
authors.lastname: Franzius
authors.forename: M
authors.initials: M
authors.lastname: Weckesser
authors.forename: E B
authors.initials: EB
authors.lastname: Ringelstein
authors.forename: O
authors.initials: O
authors.lastname: Schober
mesh_terms: D001692:Biological Transport; D005910:Glioma / Q000378:metabolism*; D006801:Humans; D008781:Methyltyrosines / Q000138:chemical synthesis / Q000493:pharmacokinetics*; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics*; D014407:Tumor Cells, Cultured / Q000378:metabolism*
chemical_list: D008781:Methyltyrosines; D019275:Radiopharmaceuticals; C030855:3-iodo-alpha-methyltyrosine