Dataset Information

Development of a triazolobenzodiazepine-based PET probe for subtype-selective vasopressin 1A receptor imaging.

ABSTRACT:

Objectives

To enable non-invasive real-time quantification of vasopressin 1A (V1A) receptors in peripheral organs, we sought to develop a suitable PET probe that would allow specific and selective V1A receptor imaging in vitro and in vivo.

Methods

We synthesized a high-affinity and -selectivity ligand, designated compound 17. The target structure was labeled with carbon-11 and tested for its utility as a V1A-targeted PET tracer by cell uptake studies, autoradiography, in vivo PET imaging and ex vivo biodistribution experiments.

Results

Compound 17 (PF-184563) and the respective precursor for radiolabeling were synthesized in an overall yield of 49% (over 7 steps) and 40% (over 8 steps), respectively. An inhibitory constant of 0.9 nM towards the V1A receptors was measured, while excellent selectivity over the related V1B, V2 and OT receptor (IC₅₀ >10,000 nM) were obtained. Cell uptake studies revealed considerable V1A binding, which was significantly reduced in the presence of V1A antagonists. Conversely, there was no significant blockade in the presence of V1B and V2 antagonists. In vitro autoradiography and PET imaging studies in rodents indicated specific tracer binding mainly in the liver. Further, the pancreas, spleen and the heart exhibited specific binding of [¹¹C]17 ([¹¹C]PF-184563) by ex vivo biodistribution experiments.

Conclusion

We have developed the first V1A-targeted PET ligand that is suitable for subtype-selective receptor imaging in peripheral organs including the liver, heart, pancreas and spleen. Our findings suggest that [¹¹C]PF-184563 can be a valuable tool to study the role of V1A receptors in liver diseases, as well as in cardiovascular pathologies.

SUBMITTER: Haider A

PROVIDER: S-EPMC8581590 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature

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Publications

Development of a triazolobenzodiazepine-based PET probe for subtype-selective vasopressin 1A receptor imaging.

Haider Achi A Xiao Zhiwei Z Xia Xiaotian X Chen Jiahui J Van Richard S RS Kuang Shi S Zhao Chunyu C Rong Jian J Shao Tuo T Ramesh Perla P Aravind Appu A Shao Yihan Y Ran Chongzhao C Young Larry J LJ Liang Steven H SH

Pharmacological research 20210916

<h4>Objectives</h4>To enable non-invasive real-time quantification of vasopressin 1A (V1A) receptors in peripheral organs, we sought to develop a suitable PET probe that would allow specific and selective V1A receptor imaging in vitro and in vivo.<h4>Methods</h4>We synthesized a high-affinity and -selectivity ligand, designated compound 17. The target structure was labeled with carbon-11 and tested for its utility as a V1A-targeted PET tracer by cell uptake studies, autoradiography, in vivo PET ...[more]

PMID: 34536549

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Dataset Information

Development of a triazolobenzodiazepine-based PET probe for subtype-selective vasopressin 1A receptor imaging.

Objectives

Methods

Results

Conclusion

Publications

Development of a triazolobenzodiazepine-based PET probe for subtype-selective vasopressin 1A receptor imaging.

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