[3H]CGP-12177, a non-selective beta-adrenoceptor antagonist, and [3H]CGP-26505, a beta 1-selective beta-adrenoceptor antagonist, were intravenously administered to rats. 94-97% of the injected radioactivity disappeared from plasma with t1/2 0.2 and 0.5 min. Total/non-specific binding ratios of 5.4 and 6.9 (CGP-12177) or 2.0 and 2.8 (CGP-26505) were maintained in heart and lung from 10 to 40 min post-injection. Labelled plasma metabolites appeared after greater than 20 min (CGP-12177) or within 2 min (CGP-26505). No metabolites were found in the heart. CGP-12177 binds to blood cells, but CGP-26505 does not. CGP-12177 can be used for PET imaging of total (beta 1 and beta 2) adrenoceptors in the heart and lung of experimental animals, but CGP-26505 is less suitable for in vivo analysis of the beta 1-subpopulation.
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http://dx.doi.org/10.1016/0883-2897(92)90130-q | DOI Listing |
Front Pharmacol
December 2017
Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom.
Recent advances in fluorescent ligand technology have enabled the study of G protein-coupled receptors in their native environment without the need for genetic modification such as addition of N-terminal fluorescent or bioluminescent tags. Here, we have used a non-imaging plate reader (PHERAstar FS) to monitor the binding of fluorescent ligands to the human adenosine-A receptor (AAR; CA200645 and AV039), stably expressed in CHO-K1 cells. To verify that this method was suitable for the study of other GPCRs, assays at the human adenosine-A receptor, and β and β adrenoceptors (βAR and βAR; BODIPY-TMR-CGP-12177) were also carried out.
View Article and Find Full Text PDFBiochem Pharmacol
January 2018
Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK. Electronic address:
Recent interest has focused on antibodies that can discriminate between different receptor conformations. Here we have characterised the effect of a monoclonal antibody (mAb3), raised against a purified thermo-stabilised turkey β-adrenoceptor (βAR-m23 StaR), on β-ARs expressed in CHO-K1 or HEK 293 cells. Immunohistochemical and radioligand-binding studies demonstrated that mAb3 was able to bind to ECL2 of the tβ-AR, but not its human homologue.
View Article and Find Full Text PDFPharmacology
September 2012
Department of Surgery II, Faculty of Medicine, University of Leipzig, Leipzig, Germany.
Aim: Hepatocellular carcinoma (HCC) is one of the most common cancers and a leading cause of death worldwide. There are now multiple lines of evidence demonstrating that the β-adrenoceptor ( β-AR) signaling plays an important role in the progression and metastasis of cancer and may become a novel target for cancer therapy. Little information exists regarding the status of β-ARs and their postreceptor intracellular signaling cascade in the development of human HCC.
View Article and Find Full Text PDFMol Pharmacol
November 2008
Institute of Cell Signaling, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
Studies with 4-[3-[(1,1-dimethylethyl)amino]2-hydroxypropoxy]-1,3-dihydro-2H-benzimidazol-2-one hydrochloride (CGP 12177) at the human beta1-adrenoceptor have provided evidence for two binding modes or conformations that have markedly different pharmacological properties. Here, key transmembrane residues (Asp104, Asp138, Ser228, Ser229, Ser232, Phe341, Asn344 and Asn363) have been mutated to provide structural insights into the nature of these conformations. [(3)H]CGP 12177 binding and cAMP response element-mediated reporter gene studies confirmed that CGP 12177 was a neutral antagonist (log K(D) = -9.
View Article and Find Full Text PDFShock
November 2006
Zakład Fizjologii Doświadczalnej, Akademia Medyczna w Białymstoku, ul. Mickiewicza 2A, PL-15-089 Białystok, Poland.
A supersensitivity of the beta-adrenoceptor-mediated chronotropic response has been demonstrated in atria isolated from rats subjected to septic shock. Our study was undertaken to investigate whether bacterial endotoxin/LPS affects the increase in heart rate induced by beta-adrenoceptor agonists in the rat also in vivo. In pithed and vagotomized rats, the nonselective beta-adrenoceptor agonist isoprenaline (0.
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