Abstract:
:1. The atrioventricular node (AVN) is an important part of the conduction system in the heart and is a significant site of antiarrhythmic drug action. The class 1 antiarrhythmic propafenone is effective in treating a variety of arrhythmias, including those involving the AVN. In this study, we have investigated the effects of propafenone on ionic currents in single rabbit AVN cells, focusing in particular on those on L-type calcium current (ICa,L). 2. With a standard K-based internal dialysis solution, exposure to 5 microM propafenone reduced significantly the amplitude of ICa,L. In spontaneously active AVN myocytes, action potential upstroke velocity was decreased by propafenone exposure, consistent with the observed change in ICa,L. 3. By use of a Cs-based internal dialysis solution to record ICa,L selectively, voltage clamp test pulses were applied from a holding potential of -40 mV to +10 mV (stimulation frequency 0.33 Hz). Propafenone 5 microM reduced mean ICa,L density at +10 mV from -9.58 +/- 1.05 pA/pF to -4.19 +/- 0.60 pA/pF (P < 0.002). A range of propafenone concentrations were applied which reduced ICa,L in a dose-dependent manner (IC50 1.7 microM). When test pulses were applied to a range of potentials, propafenone reduced ICa,L at each potential without significantly affecting the activation curve for this current. Thus, propafenone reduced ICa,L conductance, without affecting the voltage-dependent activation properties of the current. 4. ICa,L block by propafenone exhibited tonic-, use- and frequency-dependent characteristics. 5. In the presence of propafenone, the voltage-dependence of inactivation of ICa,L was shifted 8 mV in the hyperpolarizing direction. Also, the recovery of ICa,L from inactivation was slowed by propafenone. 6. The ICa,L blocking properties of propafenone may mediate some of the antiarrhythmic properties of this agent, particularly in regions of the heart such as the AVN in which ICa,L contributes significantly to the action potential upstroke.
journal_name
Br J Pharmacoljournal_title
British journal of pharmacologyauthors
Hancox JC,Mitcheson JSdoi
10.1038/sj.bjp.0701086subject
Has Abstractpub_date
1997-05-01 00:00:00pages
7-14issue
1eissn
0007-1188issn
1476-5381journal_volume
121pub_type
杂志文章abstract::The effects of the alpha- and beta-isomers of flupenthixol on 5-hydroxytryptamine (5-HT)-induced platelet aggregation and on 5-HT and dopamine uptake were investigated. Alpha-Flupenthixol was 185 times more potent than the beta-isomer as an inhibitor of platelet aggregation. In contrast both isomers were equipotent a...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1975.tb07432.x
更新日期:1975-12-01 00:00:00
abstract:BACKGROUND AND PURPOSE:AZ11645373 and N-{2-methyl-5-[(1R, 5S)-9-oxa-3,7-diazabicyclo[3.3.1]non-3-ylcarbonyl]phenyl}-2-tricyclo[3.3.1.13,7]dec-1-ylacetamide hydrochloride (compound-22) are recently described P2X(7) receptor antagonists. In this study we have further characterized these compounds to determine their mecha...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2009.00135.x
更新日期:2009-04-01 00:00:00
abstract::1 Acetylcholine, substance P, prostaglandin E1 and the nitrovasodilator glyceryl trinitrate induced concentration-dependent relaxations of endothelium-intact strips of rabbit coeliac artery precontracted with noradrenaline. 2 Endothelium-denuded strip preparations contracted to acetylcholine and showed no response to ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1987.tb11317.x
更新日期:1987-09-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Inhibitors of histone deacetylase (HDAC) are emerging as a promising class of anti-cancer drugs, but a generic deregulation of transcription in neoplastic cells cannot fully explain their therapeutic effects. In this study we evaluated alternative molecular mechanisms by which HDAC inhibitors cou...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0707608
更新日期:2008-02-01 00:00:00
abstract::GR231118 (also known as 1229U91 and GW1229), a purported Y(1) antagonist and Y(4) agonist was radiolabelled using the chloramine T method. [(125)I]-GR231118 binding reached equilibrium within 10 min at room temperature and remained stable for at least 4 h. Saturation binding experiments showed that [(125)I]-GR231118 b...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0702983
更新日期:2000-01-01 00:00:00
abstract::The rat isolated right atrium (frequency response) and progesterone-treated rat uterus (relaxation) were used to examine the beta 1- and beta 2-adrenoceptor stimulatory effects of alprenolol, oxprenolol and pindolol. In addition, the beta 1-adrenoceptor stimulatory effect of practolol was studied in the right atrium. ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1986.tb14582.x
更新日期:1986-04-01 00:00:00
abstract::1. Despite the observation of pharmacological responses to neuropeptide Y (NPY) in mammalian kidneys, there are species differences in the ease with which specific NPY binding sites can be demonstrated; we have investigated whether this can be explained by differential metabolism of NPY by a membrane-bound peptidase. ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1991.tb12429.x
更新日期:1991-10-01 00:00:00
abstract::1. The present work describes the effects of inhibitors (amiloride and ethylisopropylamiloride) and activators (quinoxaline and phenylephrine) of the Na(+)-H+ exchanger on the outflow of dopamine in rat kidney slices loaded with L-dihydroxyphenylalanine (L-DOPA). 2. Incubation of kidney slices loaded with 50 microM L-...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1993.tb13608.x
更新日期:1993-06-01 00:00:00
abstract::1. The effects of 5-hydroxytryptamine (5-HT) uptake inhibitors, agonists and antagonists have been evaluated on mouse marble-burying behaviour, a putative test for anxiolytic agents. The high levels of locomotor activity occurring on first exposure to a circular runway (runway were used as a separate test of non-speci...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1991.tb12392.x
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abstract::1. The effect of purified crotapotin, a non-toxic non-enzymatic chaperon protein normally complexed to a phospholipase A2 (PLA2) in South America rattlesnake venom, was studied in the acute inflammatory response induced by carrageenin (1 mg/paw), compound 48/80 (3 micrograms/paw) and 5-hydroxytryptamine (5-HT) (3 micr...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1995.tb17178.x
更新日期:1995-02-01 00:00:00
abstract::Obsessive-compulsive disorder (OCD) is characterized by obsessions (intrusive thoughts) and compulsions (repetitive ritualistic behaviours) leading to functional impairment. Accumulating evidence links these conditions with underlying dysregulation of fronto-striatal circuitry and monoamine systems. These abnormalitie...
journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1111/j.1476-5381.2011.01422.x
更新日期:2011-10-01 00:00:00
abstract::1. Intraplantar administration of the nitric oxide (NO) donor, sodium nitroprusside (SNP), induces hyperaemia in the rat paw skin, which is in part due to release of calcitonin gene-related peptide (CGRP) from afferent nerve fibres. The present study examined whether prostaglandins or other inflammatory mediators part...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1995.tb15081.x
更新日期:1995-11-01 00:00:00
abstract::1. Interactions of bath-applied pentobarbitone and gamma-aminobutyric acid (GABA) on neurones in isolated superior cervical ganglia of the rat have been examined with intracellular microelectrodes. 2. Pentobarbitone itself (30 micrometer-1 mM) showed no clear or consistent GABA-like effects: changes in resting input c...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1978.tb07791.x
更新日期:1978-05-01 00:00:00
abstract::1. We have investigated the effects of a standardised mixture of hydroxyethylrutosides (HR, Venoruton), a mixture of five of its main components (M) and each of the five components separately (7-mono-HR, 7,4'-di-HR, 7,3',4'-tri-HR, 5,7,3',4'-tetra-HR and 7,3'4'-tri HQ) upon the permeability of single perfused capillar...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1993.tb13792.x
更新日期:1993-09-01 00:00:00
abstract::The hypothesis of negative feedback regulation of noradrenaline release was studied in guinea-pig left atrial halves mounted in vitro. Tissues were transmurally stimulated with 30, 100 or 300 pulses at 2 Hz with pulse durations ranging from 50 mus to 2,000 mus, and the efflux of 3H-transmitter determined. The efflux o...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1983.tb10545.x
更新日期:1983-08-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Small molecule glucokinase activators (GKAs) have been associated with potent antidiabetic efficacy and hepatic steatosis in rodents. This study reports the discovery of S 50131 and S 51434, two novel GKAs with an original scaffold and an atypical pharmacological profile. EXPERIMENTAL APPROACH:A...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.12172
更新日期:2013-07-01 00:00:00
abstract::1. The role of nitic oxide (NO) derived from L-arginine in the regional vasodilator effects of endothelin-1 has been investigated in anaesthetized, spontaneously hypertensive (SH) rats in which autonomic reflexes were abolished by ganglion blockade. The experimental design incorporated animals infused with phenylephri...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb09049.x
更新日期:1992-03-01 00:00:00
abstract::1 alpha-Monofluoromethyldopa (MFMD, RMI 71963), a potent and selective enzyme-activated irreversible inhibitor of aromatic L-amino acid decarboxylase produces a substantial and long-lasting decrease in the catecholamine content of mouse brain, heart and kidney. 2 Single doses of MFMD reduce the 5-hydroxytryptamine con...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1980.tb09776.x
更新日期:1980-12-01 00:00:00
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pub_type: 杂志文章
doi:10.1111/bph.14068
更新日期:2018-06-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1989.tb12615.x
更新日期:1989-10-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The passage of drugs across the blood-brain barrier (BBB) limits the efficacy of chemotherapy in brain tumours. For instance, the anticancer drug doxorubicin, which is effective against glioblastoma in vitro, has poor efficacy in vivo, because it is extruded by P-glycoprotein (Pgp/ABCB1), multidr...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2012.02103.x
更新日期:2012-12-01 00:00:00
abstract::delta 9-Tetrahydrocannabinol (delta 9-THC) was injected into the preoptic area of the anterior hypothalamus or into the third or fourth cerebral ventricle of the conscious mouse through a chronically implanted cannula and the effects on body temperature and oxygen consumption rate were measured. At an ambient temperat...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1982.tb08802.x
更新日期:1982-02-01 00:00:00
abstract::1. The mechanisms by which nicorandil causes relaxation of rat isolated small mesenteric arteries mounted on a Mulvany myograph was investigated by use of a combination of putatively mechanism-specific antagonists. 2. In arteries precontracted by the thromboxane-mimetic, U46619, the EC50 for cromakalim and levcromakal...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1996.tb16071.x
更新日期:1996-12-01 00:00:00
abstract::1. Human big-endothelin-1 (big-ET-1) and endothelin-1 (ET-1) are equipotent as pressor agents and produce a significant change in mean arterial blood pressure (MAP) in anaesthetized guinea-pigs (2 nmol kg-1: peak delta MAP: 23 +/- 6 mmHg and 26 +/- 5 mmHg, respectively). 2. Unlike big-ET-1, big-endothelin-3 (big-ET-3)...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1991.tb12448.x
更新日期:1991-10-01 00:00:00
abstract::An investigation of the effects of gamma-aminobutyric acid (GABA) and the selective GABAB receptor agonist, baclofen, on basal and stimulated adenosine 3':5'-cyclic monophosphate (cyclic AMP) levels in slices of rat cerebral cortex has been carried out. Neither GABA nor baclofen produced any significant change in basa...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:
更新日期:1985-01-01 00:00:00
abstract::Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS, and one of the most common causes of disability in young adults. Over the last decade, new disease-modifying therapies have emerged, including monoclonal antibodies (mAbs) that provide highly targeted therapies with greater efficacy than platform th...
journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1111/bph.13780
更新日期:2017-07-01 00:00:00
abstract::1. The effect of NMDA-receptor stimulation on phosphoinositide signalling in response to the metabotropic glutamate receptor agonist 1-aminocyclopentane-1S,3R-dicarboxylic acid (1S,3R-ACPD) has been examined in neonatal rat cerebral cortex slices. 2. Total [3H]-inositol phosphate ([3H]-InsPx) accumulation, in the pres...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1994.tb13057.x
更新日期:1994-05-01 00:00:00
abstract:BACKGROUND AND PURPOSE:beta-Amyloid peptide (Abeta) is implicated in the pathogenesis of Alzheimer's disease by initiating a cascade of events from mitochondrial dysfunction to neuronal death. The metabolic enhancer piracetam has been shown to improve mitochondrial dysfunction following brain aging and experimentally i...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2010.00656.x
更新日期:2010-05-01 00:00:00
abstract::1. Isolated preparations of rat anococcygeus muscle were incubated with [3H]-noradrenaline and the efflux of radioactivity induced by stimulation of intramural sympathetic nerves was used as a measure of release of transmitter noradrenaline. Isometric contractile responses were also measured. 2. Angiotensin I (0.03 mi...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1988.tb11657.x
更新日期:1988-10-01 00:00:00
abstract::Expression of two isoforms of Rho-kinase (ROCK) and its functional role in the physiological control of smooth muscle contraction in the sheep ureter were investigated. Helical strips of the ureteric smooth muscle were stimulated by electrical field stimulation (EFS, 60 V, 1 mS, 2, 4, 8, 16 and 32 Hz, for 20 S), KCl (...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0705961
更新日期:2004-10-01 00:00:00