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Published on: February 4, 2017
99m-Technetium binding site in bone marrow mononuclear cells
Grazielle Dias Suhett1, Sergio Augusto Lopes de Souza2, Adriana Bastos Carvalho3
1Laboratório de Cardiologia Celular e Molecular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro (UFRJ), Av. Carlos Chagas Filho, 373, Bloco G. Ilha do Fundão, Cidade Universitária, Rio de Janeiro, 21941-902, Brasil. grazisuhett@gmail.com.
This study investigated technetium-99m ((99m)Tc) binding sites in rat bone marrow stem cells. Most radioactivity localized to the cytosol, indicating intracellular labeling targeting soluble molecules and unbound ribosomes.
Area of Science:
- Nuclear medicine
- Cell biology
- Biochemistry
Background:
- Growing interest in technetium-99m ((99m)Tc) labeled stem cells for medical imaging.
- Need to understand the intracellular localization of (99m)Tc within stem cells.
Purpose of the Study:
- To identify the specific cellular compartments and molecules that bind (99m)Tc in bone marrow mononuclear cells.
- To characterize the intracellular distribution of radioactivity after direct labeling with (99m)Tc.
Main Methods:
- Bone marrow mononuclear cells were isolated from rats and directly labeled with (99m)Tc.
- Cells were lysed, and organelles were separated using differential centrifugation.
- Radioactivity in each fraction (nuclei, mitochondria, microsomes, cytosol) was quantified.
Main Results:
- The (99m)Tc labeling procedure maintained cell viability.
- The majority of radioactivity (approximately 54%) was found in the cytosol fraction.
- Significant radioactivity (approximately 38.5%) was also associated with the nuclei-rich fraction.
Conclusions:
- Direct labeling of bone marrow cells with (99m)Tc primarily targets intracellular components, with the cytosol being the main repository.
- The cytosol fraction contains soluble molecules and unbound ribosomes as likely binding sites for (99m)Tc.
- Further research is needed to fully elucidate the cellular uptake and binding mechanisms of (99m)Tc in bone marrow cells.
