Abstract |
A new derivative of octreotide SDZ 219-387 [PnAO-(D)Phe(1)- octreotide] was synthesized, which binds specifically and with high affinity to somatostatin receptors in vitro (pKi = 9.79 +/- 0.16). This new somatostatin analogue chelates technetium-99m under mild labelling conditions in good yields. The resulting [99mTc] SDZ 219-387 was stable up to 6 h after labelling and could be isolated in a pure radiochemical and chemical form by high-performance liquid chromatographic purification. The intravenous administration of purified [99mTc] SDZ 219-387 revealed that the radioligand was rapidly cleared from circulation, and tumour uptake of 0.38% ID/g was observed at 1.5 h post injection. [99mTc] SDZ 219-387 specifically interacted with somatostatin binding sites on the tumour. However, the radioligand is highly lipophilic and excreted mainly through the hepatobiliary system. As a consequence, [99mTc] SDZ 219-387 exhibits increased background activity and therefore is not appropriate for the in vivo visualization of somatostatin receptor-positive tumours and/or their metastases in the abdomen.
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Authors | T Maina, B Stolz, R Albert, C Bruns, P Koch, H Mäcke |
Journal | European journal of nuclear medicine
(Eur J Nucl Med)
Vol. 21
Issue 5
Pg. 437-44
(May 1994)
ISSN: 0340-6997 [Print] Germany |
PMID | 8062850
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- (PnAO-(D)Phe(1))octreotide
- Organotechnetium Compounds
- Octreotide
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Topics |
- Animals
- Cerebral Cortex
(metabolism)
- Male
- Models, Chemical
- Octreotide
(analogs & derivatives, chemistry, pharmacokinetics)
- Organotechnetium Compounds
(chemistry, pharmacokinetics)
- Radioligand Assay
- Rats
- Rats, Inbred Lew
- Rats, Sprague-Dawley
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