Abstract:
BACKGROUND AND PURPOSE:Conventional determination of agonist efficacy at G-protein coupled receptors is measured by stimulation of guanosine-5'-γ-thiotriphosphate (GTPγS) binding. We analysed the role of guanosine diphosphate (GDP) in the process of activation of the M₂ muscarinic acetylcholine receptor and provide evidence that negative cooperativity between agonist and GDP binding is an alternative measure of agonist efficacy. EXPERIMENTAL APPROACH:Filtration and scintillation proximity assays measured equilibrium binding as well as binding kinetics of [³⁵S]GTPγS and [³H]GDP to a mixture of G-proteins as well as individual classes of G-proteins upon binding of structurally different agonists to the M₂ muscarinic acetylcholine receptor. KEY RESULTS:Agonists displayed biphasic competition curves with the antagonist [³H]-N-methylscopolamine. GTPγS (1 µM) changed the competition curves to monophasic with low affinity and 50 µM GDP produced a similar effect. Depletion of membrane-bound GDP increased the proportion of agonist high-affinity sites. Carbachol accelerated the dissociation of [³H]GDP from membranes. The inverse agonist N-methylscopolamine slowed GDP dissociation and GTPγS binding without changing affinity for GDP. Carbachol affected both GDP association with and dissociation from G(i/o) G-proteins but only its dissociation from G(s/olf) G-proteins. CONCLUSIONS AND IMPLICATIONS:These findings suggest the existence of a low-affinity agonist-receptor conformation complexed with GDP-liganded G-protein. Also the negative cooperativity between GDP and agonist binding at the receptor/G-protein complex determines agonist efficacy. GDP binding reveals differences in action of agonists versus inverse agonists as well as differences in activation of G(i/o) versus G(s/olf) G-proteins that are not identified by conventional GTPγS binding.
journal_name
Br J Pharmacoljournal_title
British journal of pharmacologyauthors
Jakubík J,Janíčková H,El-Fakahany EE,Doležal Vdoi
10.1111/j.1476-5381.2010.01081.xsubject
Has Abstractpub_date
2011-03-01 00:00:00pages
1029-44issue
5eissn
0007-1188issn
1476-5381journal_volume
162pub_type
杂志文章abstract::1. Effects of phorbol esters on the cytosolic Ca2+ level ([Ca2+]i) and muscle tension in the intestinal smooth muscle of guinea-pig taenia caeci were examined. 2. 12-Deoxyphorbol 13-isobutyrate (DPB, 1 microM) did not change the [Ca2+]i and tension in resting muscle. 3. In high K(+)-stimulated muscle, 1 microM DPB tra...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1993.tb13558.x
更新日期:1993-05-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Anxiety disorder is a common mental health disorder. However, there are few safe and fast-acting anxiolytic drugs available that can treat anxiety disorder. We previously demonstrated that the interaction of neuronal NOS (nNOS) with its carboxy-terminal PDZ ligand (CAPON) is involved in regulatin...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.15084
更新日期:2020-08-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0706182
更新日期:2005-06-01 00:00:00
abstract::1. The effects of adenosine A1 receptor stimulation on basal and histamine-stimulated levels of intracellular free calcium ion concentration ([Ca2+]i) have been investigated in primary astrocyte cultures derived from neonatal rat forebrains. 2. Histamine (0.1 microM-1 mM) caused rapid, concentration-dependent increase...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1995.tb15004.x
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abstract::The distribution of beta-adrenoceptor subtypes in slide-mounted sections of guinea-pig kidney has been examined by the technique of in vitro labelling combined with autoradiography. Binding of (-)-[125I]-cyanopindolol (Cyp) to kidney sections equilibrated and dissociated slowly, was saturable and stereoselective with ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1985.tb08867.x
更新日期:1985-06-01 00:00:00
abstract::1. We have examined the mechanisms of local oedema formation in the passive cutaneous anaphylactic (PCA) reaction in the rabbit. 2. IgE-containing antiserum was injected i.d. and allowed to sensitize skin sites for periods up to 240 h. Antigen (bovine gamma globulin) was injected i.d. or i.v. and local oedema formatio...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb13424.x
更新日期:1992-12-01 00:00:00
abstract::1 The actions and interactions of adenosine and dipyridamole were investigated on isolated strips of coronary arteries of beef cattle. It was found that small diameter arteries (about 0.5-1.0 mm o9d.), raised to a moderate level of tone with potassium, responded with relaxation to low concentrations of adenosine. 2 Di...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1975.tb06949.x
更新日期:1975-11-01 00:00:00
abstract::1. The noradrenaline (NA) concentration in the "heart" (atria and right ventricle) of male rats was estimated at different periods following adrenal demedullation. For 1-3 weeks after the operation there was, in all rats, a reduction in NA content of the tissue, whereas, after somewhat longer intervals, the concentrat...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1970.tb10335.x
更新日期:1970-01-01 00:00:00
abstract::1. The effects of tacrine (9-amino-1,2,3,4-tetrahydroacridine), velnacrine (HP029, 9-amino-1,2,3,4-tetrahydroacridin-1-ol maleate), suronacrine (HP128, 9-benzylamino-1,2,3,4-tetrahydroacridin-1-ol maleate), and 3,4-diaminopyridine on neuromuscular transmission were compared on isolated nerve-muscle preparations. 2. Ta...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1991.tb12275.x
更新日期:1991-04-01 00:00:00
abstract::1. The pharmacokinetics of cyclophosphamide were investigated in cancer patients. The data can be characterized by a two-compartment open model. The half life of the elimination phase of the drug ranged between 3 and 11 hours.2. Extensive tubular reabsorption of the drug resulted in the excretion of only a small perce...
journal_title:British journal of pharmacology
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doi:10.1111/j.1476-5381.1971.tb07199.x
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abstract::The mechanism underlying the LTC(4)-induced contraction of guinea-pig taenia coli was determined using the simultaneous measurements of [Ca(2+)](i) and force in whole muscle preparations. Additional experiments were performed in receptor coupled permeabilized preparation. For comparison purposes, the contraction which...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0704122
更新日期:2001-06-01 00:00:00
abstract::1. Flexor withdrawal reflexes to noxious mechanical pinch stimuli were recorded as single motor unit activity in alpha-chloralose anaesthetized rats, by means of tungsten bipolar electrodes inserted percutaneously into hindlimb flexor muscles. The relative spinal and supraspinal contributions to mu- and kappa-opioid a...
journal_title:British journal of pharmacology
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doi:10.1111/j.1476-5381.1991.tb12402.x
更新日期:1991-09-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Exercise is known to improve cognitive function, but the exact synaptic and cellular mechanisms remain unclear. We investigated the potential role of the serotonin (5-HT) transporter (SERT) in mediating these effects. EXPERIMENTAL APPROACH:Hippocampal long-term potentiation (LTP) and neurogenesi...
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pub_type: 杂志文章
doi:10.1111/bph.14760
更新日期:2019-09-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1976.tb07650.x
更新日期:1976-05-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Pulmonary arterial hypertension (PAH, type 1 pulmonary hypertension) has a 3-year survival of ~50% and is in need of new, effective therapies. In PAH, remodelling of the pulmonary artery (PA) increases pulmonary vascular resistance and can result in right heart dysfunction and failure. Genetic mu...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.15074
更新日期:2020-08-01 00:00:00
abstract::1. A technique for the close-arterial administration of substances to the rat stomach in vivo has been developed. 2. Intra-arterial infusion of platelet-activating factor (Paf, 10-50 ng kg-1 min-1 for 10 min) induced macroscopically assessed damage in the corpus mucosa, characterized as vasocongestion and necrosis. 3....
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1988.tb11425.x
更新日期:1988-01-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Increases in intracellular cyclic AMP (cAMP) augment the release/secretion of glucagon-like peptide-1 (GLP-1). As cAMP is hydrolysed by cAMP phosphodiesterases (PDEs), we determined the role of PDEs and particularly PDE4 in regulating GLP-1 release. EXPERIMENTAL APPROACH:GLP-1 release, PDE expre...
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journal_title:British journal of pharmacology
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doi:10.1111/j.1476-5381.1992.tb14436.x
更新日期:1992-08-01 00:00:00
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pub_type: 杂志文章
doi:10.1111/j.1476-5381.1972.tb08124.x
更新日期:1972-08-01 00:00:00
abstract::1. The affinities of a number of alpha 1-adrenoceptor antagonists were determined by displacement of [3H]-prazosin binding from cloned human alpha 1A-adrenoceptors (previously designated cloned alpha 1c subtype), alpha 1B alpha 1D and rat alpha 1D-adrenoceptors, stably expressed in rat-1 fibroblasts. Functional affini...
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更新日期:1995-07-01 00:00:00
abstract::1. An 'atypical' 5-HT2 receptor which is located on the endothelium of rat jugular vein has been described. In the present study we have further defined the nature of the 5-HT2 receptor subtype present in this preparation. 2. In experiments conducted in the presence of ketanserin to preclude involvement of 5-HT2 recep...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1995.tb13240.x
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abstract::1 The effect of potassium channel opening compounds has been investigated in the smooth muscle of rabbit aorta under Ca-free conditions. Examination of the characteristics of the response has been performed using cromakalim as the prototype compound. 2 In order of potency, Ro 31-6930, cromakalim, minoxidil sulphate an...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb13428.x
更新日期:1992-12-01 00:00:00
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journal_title:British journal of pharmacology
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journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb14430.x
更新日期:1992-08-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1980.tb10421.x
更新日期:1980-02-01 00:00:00
abstract::1. The nature and cellular mechanisms that are responsible for endothelium-dependent relaxations resistant to indomethacin and NG-nitro-L-arginine methyl ester (L-NAME) were investigated in phenylephrine (PE) precontracted isolated carotid arteries from the rabbit. 2. In the presence of the cyclo-oxygenase inhibitor, ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0700945
更新日期:1997-02-01 00:00:00
abstract::AMPA-type glutamate receptors are one of the most dynamic components of excitatory synapses. Their regulated addition and removal from synapses leads to long-lasting forms of synaptic plasticity, known as long-term potentiation (LTP) and long-term depression (LTD). In addition, AMPA receptors reach their synaptic targ...
journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1038/sj.bjp.0707525
更新日期:2008-03-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Disruptions of executive function, including attentional deficits, are a hallmark of a number of diseases. ACh in the prefrontal cortex regulates attentive behaviour; however, the role of α7 nicotinic ACh receptor (α7nAChR) in attention is contentious. EXPERIMENTAL APPROACH:In order to probe att...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.13260
更新日期:2015-10-01 00:00:00