Linked Life Data

11786277

Source:http://linkedlifedata.com/resource/pubmed/id/11786277

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2002-1-11
pubmed:abstractText
4-([(18)F]fluoro)benzoyl-neurotensin(8-13) ((18)FB-Arg(8)-Arg(9)-Pro(10)-Tyr(11)- Ile(12)-Leu(13)-OH, 1) and two analogs stabilized in one and two positions ((18)FB-Arg(8)psi(CH(2)NH)Arg(9)-Pro(10)-Tyr(11)- Ile(12)-Leu(13)-OH, 2, (18)FB-Arg(8)psi(CH(2)NH)Arg(9)-Pro(10)-Tyr(11)-Tle(12)-Leu(13)-OH, 3) were synthesized in a radiochemical yield of 25-36% and a specific activity of 5-15 GBq/mmol. The peptides were evaluated in vitro and in vivo for their potential to image tumors overexpressing neurotensin receptor 1 (NTR1) by positron emission tomography (PET). All analogs exhibited in vitro binding affinity in the low nanomolar range to NTR1-expressing human tumors, measured by quantitative receptor autoradiography, HT-29 and WiDr cells, and to sections of tumors derived from these cell lines in mice. The radiotracers were internalized in the cells in vitro, and the fluorinated peptides were able to mobilize intracellular Ca(2+) of WiDr cells. In in vivo studies in rats and in mice bearing HT-29 cell tumors, only a moderate uptake of the radioligands into the studied tumors was observed, presumed to be due to degradation in vivo and fast elimination by the kidneys. In comparison with the other analogs, the specific tumor uptake expressed as tumor-to-muscle relation was highest for the radioligand 3. The blood clearance of 3 was reduced by co-injection of peptidase inhibitors. The catabolic pathways of the radiofluorinated peptides were elucidated. The results suggest that the high binding affinity to NTR1 and the stabilization against proteolytic degradation are not yet sufficient for tumor imaging by PET.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0969-8051
pubmed:author
pubmed:issnType
Print
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
61-72
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Biodistribution and catabolism of (18)F-labeled neurotensin(8-13) analogs.
pubmed:affiliation
Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't