TY - JOUR
T1 - Synthesis and biological evaluation of Tc-99m- cyclopentadienyltricarbonyltechnetium-labeled octreotide
AU - Spradau, Todd W.
AU - Edwards, W. Barry
AU - Anderson, Carolyn J.
AU - Welch, Michael J.
AU - Katzenellenbogen, John A.
N1 - Funding Information:
We are grateful for the support of this research through grants from the National Institutes of Health (PHS 5R01 CA25836 to J. A. K. and PHS 5R29 CA64475 to C. J. A.–FIRST award) and from the Department of Energy (DE FG02 84ER60218 to M. J. W.). We thank Elizabeth L. C. Sherman and Michael Cristel for assistance with animal experiments.
PY - 1999/1
Y1 - 1999/1
N2 - Octreotide was labeled at its N-terminus with Tc-99m- cyclopentadienyltricarbonyltechnetium, and the biodistribution of the labeled conjugate was studied in adult female Sprague-Dawley rats. The synthesis began with the preparation of Tc-99m-(methoxycarbonylcyclopentadienyl) tricarbonyltechnetium from Tc-99m-pertechnetate using a novel double ligand transfer reaction; it was completed in a total of five steps, with an 8% overall radiochemical yield (15% decay-corrected). The 99mTc- cyclopentadienyltricarbonyltechnetium-labeled octreotide conjugate (99mTc- CpTT-octreotide) showed receptor-mediated uptake in the pancreas and adrenals, which was blocked (80% and 93%, respectively) by excess unlabeled octreotide. These studies illustrate a new method for labeling a peptide with Tc-99m through an organometallic linkage that is stable, nonpolar, and low molecular weight; it complements labeling approaches that utilize inorganic metal complexes.
AB - Octreotide was labeled at its N-terminus with Tc-99m- cyclopentadienyltricarbonyltechnetium, and the biodistribution of the labeled conjugate was studied in adult female Sprague-Dawley rats. The synthesis began with the preparation of Tc-99m-(methoxycarbonylcyclopentadienyl) tricarbonyltechnetium from Tc-99m-pertechnetate using a novel double ligand transfer reaction; it was completed in a total of five steps, with an 8% overall radiochemical yield (15% decay-corrected). The 99mTc- cyclopentadienyltricarbonyltechnetium-labeled octreotide conjugate (99mTc- CpTT-octreotide) showed receptor-mediated uptake in the pancreas and adrenals, which was blocked (80% and 93%, respectively) by excess unlabeled octreotide. These studies illustrate a new method for labeling a peptide with Tc-99m through an organometallic linkage that is stable, nonpolar, and low molecular weight; it complements labeling approaches that utilize inorganic metal complexes.
KW - Cyclopentadienyltricarbonyltechnetium
KW - Double ligand transfer
KW - Octreotide
KW - Somatostatin
KW - Technetium- 99m
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U2 - 10.1016/S0969-8051(98)00060-2
DO - 10.1016/S0969-8051(98)00060-2
M3 - Article
C2 - 10096494
AN - SCOPUS:0032939815
SN - 0969-8051
VL - 26
SP - 1
EP - 7
JO - International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology
JF - International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology
IS - 1
ER -