Direct n.c.a. electrophilic radioiodination of tyrosine analogues; their in vivo stability and brain-uptake in mice

Krummeich, C.; Holschbach, M.; Stöcklin, G.

doi:10.1016/0969-8043(94)90230-5

Cited by 44 publications

(18 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…123 I-IMT was synthesized from L-α-methyltyrosine through the iodination of the C3 position of the benzene ring as described previously [15]. Bovine serum albumin (which was used to determine the protein content of the cells), the amino acids L-leucine, L-isoleucine, L-phenylalanine, L-arginine, L-lysine, and L-alanine, α-(methylamino)isobutyric acid (MeAIB), 2-aminobicyclo[2.2.1] heptane-2-carboxylic acid (BCH) and Krebs-Ringer bicarbonate buffered medium were obtained from Sigma-Aldrich (Germany).…”

Section: Chemicals and Reagentsmentioning

confidence: 99%

Kinetics of 3-[123I]iodo-l-α-methyltyrosine transport in rat C6 glioma cells

et al. 1999

View full text Add to dashboard Cite

3-[(123)I]Iodo-l-alpha-methyltyrosine ((123)I-IMT) is used for the diagnosis and monitoring of brain tumours by means of single-photon emission tomography (SPET). To date, little has been known about the system for the transport of (123)I-IMT into brain tumour cells. It is assumed that (123)I-IMT is transported by a specific carrier for large, neutral amino acids (L-system). In this study, rat C6 glioma cells were used to characterize the uptake system of (123)I-IMT and to investigate its precise kinetics. The time course of (123)I-IMT uptake into the cells was examined for a range of 1-60 min. (123)I-IMT uptake rates with varying concentrations of (123)I-IMT (2. 5-50 microM) in the medium were quantified to assess the kinetic parameters of (123)I-IMT transport. Furthermore, competition of (123)I-IMT with other amino acids was investigated to identify the distinct transport systems involved in (123)I-IMT uptake. (123)I-IMT uptake into C6 glioma cells was linear for approximately 10 min and reached a steady-state level within 30 min. The analysis of the rate of uptake of (123)I-IMT at different concentrations was concordant with the predominance of a single uptake system. The apparent Michaelis constant (K(m)) of (123)I-IMT was 26.2+/-1.9 microM, and the maximum transport velocity (V(max)) was 35.4+/-1.7 nmol/mg protein per 10 min. 77%+/-10% of (123)I-IMT transport was sodium independent and 23%+/-3% was sodium dependent. Competitive inhibition of (123)I-IMT uptake by 2-aminobicyclo[2.2. 1]heptane-2-carboxylic acid, alpha-(methylamino)isobutyric acid and naturally occurring amino acids revealed a major (123)I-IMT transport via the sodium-independent system L (72%) and a minor uptake via the sodium-dependent system B(0,+) (17%). Our results show that (123)I-IMT transport into C6 glioma cells is principally mediated by the L-system and to a minor extent by the B(0,+)-system. The kinetic parameters of (123)I-IMT uptake are in the range of those of naturally occurring amino acids.

show abstract

Section: Chemicals and Reagentsmentioning

confidence: 99%

Kinetics of 3-[123I]iodo-l-α-methyltyrosine transport in rat C6 glioma cells

et al. 1999

View full text Add to dashboard Cite

show abstract

“…For the preparation of IMT, a modified method described previously by Krummreich et al [26] was used. All patients fasted overnight before the IMT-SPECT studies.…”

Section: Spect Imagingmentioning

confidence: 99%

Combined SPECT/CT imaging using 123I-IMT in the detection of recurrent or persistent head and neck cancer

Plotkin¹,

Würm

Eisenacher³

et al. 2005

Eur Radiol

View full text Add to dashboard Cite

The aim of the study was to assess the clinical value of combined SPECT/CT imaging using L: -3-[123I]iodine-alpha-methyl tyrosine (IMT) for the differential diagnosis of recurrences in patients pre-treated for head and neck cancer. Thirty-four consecutive patients with biopsy-proven carcinomas, who had previously been treated by surgery and/or radio/chemotherapy, were examined at our clinic by IMT-SPECT using a dual-head system with integrated low-dose CT. SPECT results were correlated with histopathology, clinical and CT/MRI follow-up data. In the follow-up after SPECT examination, the final diagnosis of recurrent tumour was established in 26 patients; the remaining eight patients were recurrence-free (follow-up >6 months). IMT-SPECT/CT correctly detected recurrent disease and/or neck lymph node metastases in 22 patients. In addition, distant metastases were displayed in two patients. The study was false-negative in four patients (sensitivity 85%). True-negative results were registered in seven patients, and false-positive in one patient. Image fusion with coregistered low-dose CT facilitates the localisation and interpretation of IMT-SPECT findings. IMT-SPECT using integrated low-dose CT is a promising non-invasive imaging tool for the detection of head and neck cancer recurrences and their differentiation from treatment-induced changes.

show abstract

“…[ 123 I]-IMT was synthesized from L-α-methyltyrosine by radioiodination of the C3 position of the benzene ring as described previously [27].…”

Section: Chemicals and Reagentsmentioning

confidence: 99%

Early Effects of Irradiation on [123I]-IMT and [18F]-FDG Uptake in Rat C6 Glioma Cells

et al. 2004

View full text Add to dashboard Cite

show abstract

Direct n.c.a. electrophilic radioiodination of tyrosine analogues; their in vivo stability and brain-uptake in mice

Cited by 44 publications

References 6 publications

Kinetics of 3-[123I]iodo-l-α-methyltyrosine transport in rat C6 glioma cells

Kinetics of 3-[123I]iodo-l-α-methyltyrosine transport in rat C6 glioma cells

Combined SPECT/CT imaging using 123I-IMT in the detection of recurrent or persistent head and neck cancer

Early Effects of Irradiation on [123I]-IMT and [18F]-FDG Uptake in Rat C6 Glioma Cells

Contact Info

Product

Resources

About