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Evaluation of 99mTc-MAG3-annexin V: influence of the chelate on in vitro and in vivo properties in mice
- Source :
- Nuclear Medicine and Biology. 33:135-144
- Publication Year :
- 2006
- Publisher :
- Elsevier BV, 2006.
-
Abstract
- We conjugated mercaptoacetyltriglycine (MAG(3)) to rh-annexin V to permit radiolabeling with (99m)Tc in an effort to decrease the high kidney and liver accumulation observed for (99m)Tc-labeled Hynic-annexin V. The 36-kDa protein was conjugated at a 5:1 molar ratio with NHS-MAG(3) in HEPES buffer pH 7.8 at room temperature, then quenched with glycine and purified by dialysis. The biopotency of the resulting MAG(3)-annexin was similar to that of Hynic-annexin as determined by a sensitive red blood cell membrane affinity binding assay and a surface plasmon resonance (SPR) assay. The (99m)Tc radiolabeling of MAG(3)-annexin resulted in radiochemical yields of 90% under mildly basic pH conditions. Biodistribution data in normal mice clearly showed a significant decrease in kidney and liver uptake at 1 h postinjection for the (99m)Tc MAG(3)-annexin compared to the (99m)Tc Hynic-annexin (from 24% ID to 4% ID for the liver, and 45% ID to 15% ID for the kidneys, respectively). Autoradiography of the kidneys showed retention of radioactivity in the collecting tubules following administration of both labeled annexins. The (99m)Tc MAG(3)-annexin biodistribution was also characterized by a lower retention of radioactivity in the whole body, but with small intestine accumulation over fivefold higher than observed with (99m)Tc Hynic-annexin. These findings show a definite improvement in renal and hepatic clearance of the MAG(3) radioligand. However, due to the increased radioactivity uptake in the small intestines, the early in vivo detection of ongoing apoptosis in the lower abdomen might be more difficult with (99m)Tc MAG(3)-annexin. Nevertheless, (99m)Tc MAG(3)-annexin may be an attractive alternative to (99m)Tc Hynic-annexin for the in vivo imaging of phosphatidylserine receptors.
- Subjects :
- Male
Cancer Research
Biodistribution
Metabolic Clearance Rate
Drug Evaluation, Preclinical
Technetium Tc 99m Mertiatide
Mice
Annexin
In vivo
Organometallic Compounds
medicine
Radioligand
Animals
Tissue Distribution
Radiology, Nuclear Medicine and imaging
Chelating Agents
Kidney
Chemistry
Molecular biology
In vitro
Small intestine
Red blood cell
medicine.anatomical_structure
nervous system
Biochemistry
Organ Specificity
Molecular Medicine
Radiopharmaceuticals
Oligopeptides
Subjects
Details
- ISSN :
- 09698051
- Volume :
- 33
- Database :
- OpenAIRE
- Journal :
- Nuclear Medicine and Biology
- Accession number :
- edsair.doi.dedup.....d0bcdd0d5124cb742c28f91784d98f03
- Full Text :
- https://doi.org/10.1016/j.nucmedbio.2005.09.002