title: Functional screening of adrenergic receptors by measuring intracellular calcium using the FlexStation scanning fluorimeter.
abstract: In this study we test whether functional screening of compounds to adrenergic G protein-coupled receptors (GPCRs) would provide data that correlated significantly with radiolabeled binding data, thereby permitting researchers to replace expensive radioligand-binding experiments with non-radioactive screening. An increase in intracellular calcium levels represents an important second messenger signal for several recombinant GPCRs. In this study, we describe the affinities of three alpha adrenoceptor antagonists (terazosin, tamsulosin and alfuzosin), determined by monitoring the changes in intracellular calcium levels and comparing them with their radioligand-binding affinities. In addition to determining the functional affinities of the three alpha adrenoceptor antagonists, we evaluate their binding at two alpha adrenoceptor subtypes and optimized the assay for high-throughput screening.
authors.affiliation: Department of Pharmacology, Ranbaxy Research Laboratories, Gurgaon, Haryana, India. kamna.nanda@ranbaxy.com
authors.forename: Kamna
authors.initials: K
authors.lastname: Nanda
authors.forename: Mou
authors.initials: M
authors.lastname: Chatterjee
authors.forename: Suman
authors.initials: S
authors.lastname: Gupta
authors.forename: Rakesh
authors.initials: R
authors.lastname: Singh
authors.forename: Atul
authors.initials: A
authors.lastname: Tiwar
authors.forename: Dikshi
authors.initials: D
authors.lastname: Gupta
authors.forename: Abhijit
authors.initials: A
authors.lastname: Ray
mesh_terms: D000818:Animals; D001709:Biotechnology / Q000379:methods*; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D005456:Fluorescent Dyes / Q000494:pharmacology; D005470:Fluorometry / Q000295:instrumentation* / Q000379:methods; D019204:GTP-Binding Proteins / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D011224:Prazosin / Q000031:analogs & derivatives / Q000494:pharmacology; D011485:Protein Binding; D011799:Quinazolines / Q000494:pharmacology; D011941:Receptors, Adrenergic / Q000378:metabolism; D015398:Signal Transduction; D013449:Sulfonamides / Q000494:pharmacology; D000077409:Tamsulosin
chemical_list: D005456:Fluorescent Dyes; D011799:Quinazolines; D011941:Receptors, Adrenergic; D013449:Sulfonamides; C041226:Terazosin; C047638:alfuzosin; D019204:GTP-Binding Proteins; D000077409:Tamsulosin; D002118:Calcium; D011224:Prazosin