Background: The melanin-concentrating hormone receptor 1 (MCHR1), which is highly expressed in the lateral hypothalamus, plays a key role in energy homeostasis, obesity and other endocrine diseases. Hence, there is a major interest in in vivo imaging of this receptor. A PET tracer would allow non-invasive in vivo visualization and quantification of the MCHR1. The aim of the study was the ex vivo evaluation of the MCHR1 ligand [(18)F]FE@SNAP as a potential PET tracer for the MCHR1.
Methods: [(18)F]FE@SNAP was injected directly into the jugular vein of awake naïve rats for ex vivo brain autoradiography, biodistribution and additional blood metabolite analysis. Blocking experiments were conducted using the unlabeled MCHR1 ligand SNAP-7941.
Results: A high uptake of [(18)F]FE@SNAP was observed in the lateral hypothalamus and the ventricular system. Both regions were significantly blocked by SNAP-7941. Biodistribution evinced the highest uptake in the kidneys, adrenals, lung and duodenum. Specific blocking with SNAP-7941 led to a significant tracer reduction in the heart and adrenals. In plasma samples, 47.73 ± 6.1 % of a hydrophilic radioactive metabolite was found 45 min after tracer injection.
Conclusions: Since [(18)F]FE@SNAP uptake was significantly blocked in the lateral hypothalamus, there is strong evidence that [(18)F]FE@SNAP is a highly suitable agent for specific MCHR1 imaging in the central nervous system. Additionally, this finding is supported by the specific blocking in the ventricular system, where the MCHR1 is expressed in the ependymal cells. These findings suggest that [(18)F]FE@SNAP could serve as a useful imaging and therapy monitoring tool for MCHR1-related pathologies.
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http://dx.doi.org/10.1186/s13550-016-0186-7 | DOI Listing |
Cancer Sci
January 2025
Hepatobiliary Surgery Center, Department of General Surgery, Huashan Hospital, Fudan University, Shanghai, China.
Immunotherapy has revolutionized cancer treatment, making it a challenge to noninvasively monitor immune infiltration. Metabolic reprogramming in cancers, including hepatocellular carcinoma (HCC), is closely linked to immune status. In this study, we aimed to evaluate the ability of carbon-11 acetate (C-acetate) and fluorine-18 fluorodeoxyglucose (F-FDG) PET/CT findings in predicting overall survival (OS) and immune infiltration in HCC patients.
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January 2025
Department of Biological Engineering, Massachusetts Institute of Technology; Cambridge, MA, USA, 02139; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology; Cambridge, MA, USA, 02139; Department of Chemical Engineering, Massachusetts Institute of Technology; Cambridge, MA, USA, 02139; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard University; Cambridge, MA, USA, 02139; Howard Hughes Medical Institute; Chevy Chase, MD, USA, 20815; Department of Materials Science of Engineering; Massachusetts Institute of Technology; Cambridge, MA, USA, 02139. Electronic address:
mRNA delivered using lipid nanoparticles (LNPs) has become an important subunit vaccine modality, but mechanisms of action for mRNA vaccines remain incompletely understood. Here, we synthesized a metal chelator-lipid conjugate enabling positron emission tomography (PET) tracer labeling of LNP/mRNA vaccines for quantitative visualization of vaccine trafficking in live mice and non-human primates (NHPs). Following i.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Neuroscience Research Institute, Gachon University, Incheon 21565, Republic of Korea.
To elucidate the potential roles of presynaptic and postsynaptic serotonergic activity in impulsivity traits, we investigated the relationship between self-reported impulsiveness and serotonin transporter (5-HTT) and 5-HT2A receptors in healthy individuals. In this study, 26 participants completed 3-Tesla magnetic resonance imaging and positron emission tomography with [C]DASB and [C]MDL100907. To quantify 5-HTT and 5-HT2A receptor availability, the binding potential (BP) of [C]DASB and [C]MDL100907 was derived using the simplified reference tissue model with cerebellar gray matter as the reference region.
View Article and Find Full Text PDFDiagnostics (Basel)
January 2025
Division of Nuclear Medicine, Imaging Institute of Southern Switzerland, Ente Ospedaliero Cantonale, 6500 Bellinzona, Switzerland.
Here, we describe the case of a 74-year-old male patient with a high-risk prostate carcinoma who underwent positron-emission tomography/computed tomography (PET/CT) with [Ga]Ga-prostate-specific membrane antigen ([Ga]Ga-PSMA-11) for staging. [Ga]Ga-PSMA-11 PET/CT detected an extensive area of increased tracer uptake at the prostatic level, involving both lobes. Additionally, a rounded lesion approximately 4 cm in diameter was identified in the celiac region adjacent to the stomach, exhibiting moderate tracer uptake.
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January 2025
From the School of Biomedical Engineering (B.C., H.H., J.L., S.Y., Y.C., J.L.), Shanghai Jiao Tong University, Shanghai, China; Department of Neurosurgery (S.J., J.H., L.C.), and PET Center (W.B.), Huashan Hospital, Fudan University, Shanghai, China.
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