title: Differential discrimination of G-protein coupling of serotonin(1A) receptors from bovine hippocampus by an agonist and an antagonist.
abstract: We have studied the effect of guanosine-5'-O-(3-thiotriphosphate) (GTP-gamma-S), a non-hydrolyzable analogue of GTP, on agonist and antagonist binding to bovine hippocampal 5-hydroxytryptamine (5-HT)(1A) receptor in native membranes. Our results show that the specific binding of the agonist is inhibited with increasing concentrations of GTP-gamma-S along with a reduction in binding affinity. In sharp contrast to this, antagonist binding to 5-HT(1A) receptor shows no significant reduction and remains invariant over a large range of GTP-gamma-S concentrations. The binding affinity of the antagonist also remains unaltered. This shows that the agonist and the antagonist differentially discriminate G-protein coupling of 5-HT(1A) receptors from bovine hippocampus.
authors.affiliation: Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, India.
authors.forename: K G
authors.initials: KG
authors.lastname: Harikumar
authors.forename: A
authors.initials: A
authors.lastname: Chattopadhyay
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D000631:Aminopyridines / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006150:Guanine Nucleotides / Q000378:metabolism / Q000494:pharmacology; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D010879:Piperazines / Q000378:metabolism* / Q000494:pharmacology; D011985:Receptors, Serotonin / Q000378:metabolism*; D044263:Receptors, Serotonin, 5-HT1; D012702:Serotonin Antagonists / Q000378:metabolism / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000378:metabolism / Q000494:pharmacology; D015398:Signal Transduction
chemical_list: D000631:Aminopyridines; D006150:Guanine Nucleotides; D010879:Piperazines; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C011799:5-hydroxy-2-N,N-dipropylaminotetralin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; C099463:4-(2' methoxyphenyl)-1-(2'-(N-(2''-pyridinyl)-4-fluorobenzamido)ethyl)piperazine; D019204:GTP-Binding Proteins