Small peptide-based compounds have attracted an enormous interest as carrier molecules to selectively de- liver radionuclides to target tissues, sparing critical normal organs. When looking for "matched pairs&quo...Small peptide-based compounds have attracted an enormous interest as carrier molecules to selectively de- liver radionuclides to target tissues, sparing critical normal organs. When looking for "matched pairs" of radionuclides, suitable for radiolabeling of peptides for diagnosis and therapy, technetium and rhenium represent an almost ideal constellation. The important role of technetium-99m and Re-186/188 is based on the decay characteristics, suitable for tumor diagnosis and therapy. Tc-99m and Re-188 are readily available by either a 99Mo/99mTc or the 188W/188Re ra- dionuclide generator system. Furthermore, technetium and rhenium are chemically related and share structural as well as reactive similarities, which prompt an attractive "matched-pair" situation. This article shows an overview of 99mTc- and 186/188Re-radiolabeled peptides that have been tested for their potential use as imaging and therapeutic agents in oncological diseases.展开更多
To characterize the preclinical pharmacokinetics, tissue distribution and excretion profiles of exendin-4 in healthy Wistar rats were studied. Exendin-4 was radioiodinated by the IODOGEN （1,3,4,6-tetrachloro-3 alpha,...To characterize the preclinical pharmacokinetics, tissue distribution and excretion profiles of exendin-4 in healthy Wistar rats were studied. Exendin-4 was radioiodinated by the IODOGEN （1,3,4,6-tetrachloro-3 alpha, 6 alphadiphenylglucoluril） method. Pharrnacokinetic properties of ^125I-exendin-4 were examined after a single s.c. and i.v. injection, respectively. Tissue distri- bution and urinary, fecal, and biliary excretion patterns of ^125I-exendin-4 were also investigated following a single s.c. injection. Exendin-4 was rapidly distributed and cleared with t1/2 of （0.48 ± 0.03） h after a single i.v. injection. Following a single s.c. administration, exendin-4 exhibited rapid and considerable absorption with Tmax of （0.25± 0.02） h and declined with the elimination t1/2 of（1.28± 0.14） h. The absolute bioavailability was （65.5 ± 10.2） %. The radioactivity was widely distributed and rapidly diminished in most tissues. The kidney contained the highest radioactivity and the distribution of ^125I-exendin-4 to the brain was minimal. The major elimination route was urinary excretion. The pharmacokinetic properties of exendin-4 obtained from the present study closely matched those reported in previous studies in rats. Pharmacokinetics profiles of exendin-4 in rats are warranted for the design of future clinical trials.展开更多
文摘Small peptide-based compounds have attracted an enormous interest as carrier molecules to selectively de- liver radionuclides to target tissues, sparing critical normal organs. When looking for "matched pairs" of radionuclides, suitable for radiolabeling of peptides for diagnosis and therapy, technetium and rhenium represent an almost ideal constellation. The important role of technetium-99m and Re-186/188 is based on the decay characteristics, suitable for tumor diagnosis and therapy. Tc-99m and Re-188 are readily available by either a 99Mo/99mTc or the 188W/188Re ra- dionuclide generator system. Furthermore, technetium and rhenium are chemically related and share structural as well as reactive similarities, which prompt an attractive "matched-pair" situation. This article shows an overview of 99mTc- and 186/188Re-radiolabeled peptides that have been tested for their potential use as imaging and therapeutic agents in oncological diseases.
基金National High Technology 863 Project (Grant No. 2003AA2Z347B)
文摘To characterize the preclinical pharmacokinetics, tissue distribution and excretion profiles of exendin-4 in healthy Wistar rats were studied. Exendin-4 was radioiodinated by the IODOGEN （1,3,4,6-tetrachloro-3 alpha, 6 alphadiphenylglucoluril） method. Pharrnacokinetic properties of ^125I-exendin-4 were examined after a single s.c. and i.v. injection, respectively. Tissue distri- bution and urinary, fecal, and biliary excretion patterns of ^125I-exendin-4 were also investigated following a single s.c. injection. Exendin-4 was rapidly distributed and cleared with t1/2 of （0.48 ± 0.03） h after a single i.v. injection. Following a single s.c. administration, exendin-4 exhibited rapid and considerable absorption with Tmax of （0.25± 0.02） h and declined with the elimination t1/2 of（1.28± 0.14） h. The absolute bioavailability was （65.5 ± 10.2） %. The radioactivity was widely distributed and rapidly diminished in most tissues. The kidney contained the highest radioactivity and the distribution of ^125I-exendin-4 to the brain was minimal. The major elimination route was urinary excretion. The pharmacokinetic properties of exendin-4 obtained from the present study closely matched those reported in previous studies in rats. Pharmacokinetics profiles of exendin-4 in rats are warranted for the design of future clinical trials.
