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 levcromakalim-induced relaxation curves were raised by 36 and 17 fold by glibenclamide (3 microM) while the EC50 for nicorandil-induced relaxation was unaffected by either glibenclamide or methylene blue (10 microM). A combination of these antagonists raised the EC50 for nicorandil by 8 fold. 3. In U46619-contracted arteries, nifedipine (100 nM) did not affect the cromakalim relaxation curve but it raised the EC50 for nicorandil by 5 fold. The combination of methylene blue, glibenclamide and nifedipine further inhibited the maximum relaxation to nicorandil. 4. In separate experiments, membrane potential (Em) and force responses were measured simultaneously. In arteries depolarized and contracted by U46619 both nicorandil and cromakalim repolarized (delta Em, 35 mV) and relaxed (100%) the vessels. Glibenclamide (3 microM) did not alter the relaxation-concentration curve to nicorandil but reduced the maximum repolarization to delta 10.8 mV. In contrast to Em and relaxation-response curves to cromakalim were shifted to the right by glibenclamide by 30-100 fold. 5. In unstimulated arteries, nicorandil (but not cromakalim) -induced hyperpolarization was significantly antagonized by methylene blue (10 microM) (6.6 fold rightward shift) or nifedipine (100 nM) (2.6 fold). In depolarized arteries (U46619), nifedipine but not methylene blue inhibited the nicorandil-induced hyperpolarization. 6. In arteries precontracted to 50% tissue maximum by either KCl or U46619, nifedipine (100 nM) relaxed the artery but failed to repolarize the Em. Presumably voltage-operated calcium channels (VOCC) were blocked preventing contraction but the artery remained depolarized, presumably through non VOCC mechanisms. 7. These data suggest that nicorandil may relax small arteries through 3 parallel pathways, (i) NO-donor mediated stimulation of guanylate cyclase and increase in cyclic GMP, (ii) K+ATP channel opening, and (iii) nifedipine-sensitive VOCC inhibition. Em data suggest that nicorandil-induced repolarization is caused principally through opening K+ATP channels. Blockade of this hyperpolarization by glibenclamide is not sufficient to alter the relaxation, indicating dissociation of nicorandil-induced changes in membrane potential and relaxation. 8. These results highlight the 'chameleon' actions of nicorandil where there is no apparent association of Em repolarization with relaxation, in contrast to the parallel responses for cromakalim.
journal_name
Br J Pharmacoljournal_title
British journal of pharmacologyauthors
Fujiwara T,Angus JAdoi
10.1111/j.1476-5381.1996.tb16071.xsubject
Has Abstractpub_date
1996-12-01 00:00:00pages
1549-56issue
8eissn
0007-1188issn
1476-5381journal_volume
119pub_type
杂志文章abstract::1. The possible mechanisms of action of the inhibitory effect of gomisin C on the respiratory burst of rat neutrophils in vitro was investigated. 2. The peptide formyl-Met-Leu-Phe (FMLP) induced superoxide anion (O2-) formation and O2 consumption, which was inhibited by gomisin C in a concentration-dependent manner (I...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1994.tb17084.x
更新日期:1994-11-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Tetracyclines were recently found to induce tumour cell death, but the early processes involved in this cytotoxic effect remain unclear. EXPERIMENTAL APPROACH:Viability of human and mouse melanoma cells was determined by MTT assay and flow cytometry. Kinase/protein/caspase activation was measure...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2010.00746.x
更新日期:2010-07-01 00:00:00
abstract::The endogenous concentrations of p- and m-hydroxyphenylacetic acid in the mouse caudate nucleus were determined by a gas chromatographic or a gas chromatographic-mass spectrometric technique and the concentrations were about 30 and 11 ng g-1 respectively. The subcutaneous administration of (+)-butaclamol (1 mg kg-1), ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1983.tb10732.x
更新日期:1983-11-01 00:00:00
abstract::1. The aim of this study was to characterize the tachykinin NK2 receptor subtype mediating the spasmogenic response in the human isolated bronchus. The motor response to neurokinin A (NKA) and the selective NK2 agonist [beta Ala8]NKA(4-10), as well as the antagonistic effects of cyclic (L659,877) and linear (MEN 10376...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1994.tb14775.x
更新日期:1994-02-01 00:00:00
abstract::1. The rate of gastric emptying was measured directly in 14 convalescent hospital patients and paracetamol absorption was studied following an oral dose of 1.5 g.2. Rapid gastric emptying was associated with the early appearance of high peak plasma paracetamol concentrations whereas peak concentrations were low and oc...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1973.tb08339.x
更新日期:1973-02-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Hepatic encephalopathy is a neuropsychiatric disorder of complex pathogenesis caused by acute or chronic liver failure. We investigated the effects of cannabidiol, a non-psychoactive constituent of Cannabis sativa with anti-inflammatory properties that activates the 5-hydroxytryptamine receptor 5...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2010.01179.x
更新日期:2011-04-01 00:00:00
abstract::1. A wide panel of compounds acting on beta-adrenoceptors active either in mammalian heart or in rodent digestive tract and adipose tissues, were investigated for their effects on Chinese hamster ovary cells transfected with the human or murine beta 3-adrenoceptor gene. 2. The beta 3-agonists, bucindolol, CGP 12177A a...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1994.tb13167.x
更新日期:1994-07-01 00:00:00
abstract::1 Rat isolated perfused hearts with the right sympathetic nerves attached were loaded with [3H]-(-)-noradrenaline. The nerves were stimulated with up to 40 trains of 10 pulses every min at 1 Hz, and the evoked increases of [3H-]noradrenaline overflow into the perfusate, of right atrial tension development and ventricu...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1983.tb10502.x
更新日期:1983-05-01 00:00:00
abstract::1. Catecholamine release from cat adrenal glands perfused at a high rate (4 ml min-1) at 37 degrees C with modified Krebs solutions lacking Ca and containing 1.2 mM K (hyperpolarizing solution) or 118 mM K (depolarizing solution) was triggered by 10-s pulses of Ca (0.5 mM) in the presence of 118 mM K. Hyperpolarized g...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1989.tb11874.x
更新日期:1989-03-01 00:00:00
abstract::The effect of trimetazidine (TMZ), an anti-anginal drug, on the mechanical response of the guinea-pig ductus arteriosus placed under conditions of mild hypoxia (PO2 approximately equal to 75 mmHg) was investigated. When the PO2 of the bathing solution was 75 mmHg, TMZ caused a dose-dependent increase in tension. The m...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1985.tb12936.x
更新日期:1985-02-01 00:00:00
abstract::1. Dopamine efflux following single pulse or train of pulse stimulations was measured in slices of rat caudate putamen, nucleus accumbens and tuberculum olfactorium, using fast cyclic voltammetry at a carbon fibre microelectrode; 1, 5, 10, 20 or 50 pulses were applied at each location at frequencies varying from 10 Hz...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb14355.x
更新日期:1992-06-01 00:00:00
abstract::1. The present study characterized highly effective agonists from different classes of compounds for the neuronal octopamine receptor (OAR3) of the migratory locust (Locusta migratoria L.). Biogenic amines and phenyliminoimidazolidines (PIIs) were employed for the study of structure-activity relationships. 2. The high...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1995.tb14927.x
更新日期:1995-01-01 00:00:00
abstract:BACKGROUND AND PURPOSE:There is increasing evidence that angiotensin II (Ang II) is associated with the occurrence of ventricular arrhythmias. However, little is known about the electrophysiological effects of Ang II on ventricular repolarization. The rapid component of the delayed rectifier K(+) current (I(Kr)) plays ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/bjp.2008.95
更新日期:2008-05-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Palmitoylethanolamide (PEA) is an endogenous congener of anandamide and potentiates its actions at cannabinoid CB1 and CB2 receptors, and at transient receptor potential vanilloid type-1 (TRPV1) channels. The other endocannabinoid, 2-arachidonoylglycerol (2-AG), was recently suggested to act as a...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.13084
更新日期:2016-04-01 00:00:00
abstract::The nature of the neurohypophyseal peptide receptor in the anococcygeus muscles from male mice was investigated. The rank order of potency of naturally occurring peptides was oxytocin greater than Arg-vasotocin greater than Arg-vasopressin greater than Lys-vasopressin, which is similar to that found in the uterus and ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1986.tb09482.x
更新日期:1986-05-01 00:00:00
abstract::1. We examined the effects of selective and nonselective cyclo-oxygenase (COX) inhibitors on various functional changes in the rat stomach induced by topical application of taurocholate (TC) and investigated the preferential role of COX isozymes in these responses. 2. Rat stomachs mounted in ex vivo chambers were perf...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0701399
更新日期:1997-10-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Non-invasive in vivo imaging of cannabinoid CB2 receptors using PET is pursued to study neuroinflammation. The purpose of this study is to evaluate the in vivo binding specificity of [18 F]MA3, a CB2 receptor agonist, in a rat model with local overexpression of human (h) CB2 receptors. METHODS:[...
journal_title:British journal of pharmacology
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更新日期:2019-05-01 00:00:00
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journal_title:British journal of pharmacology
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doi:10.1038/sj.bjp.0705973
更新日期:2004-12-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1996.tb15631.x
更新日期:1996-08-01 00:00:00
abstract::1. The goal of this study was to investigate the effects of the delayed pharmacological preconditioning produced by an adenosine A(1)-receptor agonist (A(1)-DPC) against ventricular arrhythmias induced by ischaemia and reperfusion, compared to those of ischaemia-induced delayed preconditioning (I-DPC). 2. Eighty-nine ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0704407
更新日期:2001-12-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1971.tb09934.x
更新日期:1971-01-01 00:00:00
abstract::1. In the neuronally isolated cortex of the cat, local application of bemegride, picrotoxin, nikethamide, caffeine and strychnine facilitated the surface positive response of the isolated cortex and lowered the stimulus threshold for this response. Excepting nikethamide, they all produced convulsive discharge in the i...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1970.tb09897.x
更新日期:1970-08-01 00:00:00
abstract::A method is described for the determination of halothane-induced sleeping time in the rat. 2 The sleeping time exhibited a diurnal variation which was due, at least in part, to a change in the sensitivity of the central nervous system (CNS) to the anaesthetic. 3 Tolerance to halothane did not develop in rats repeatedl...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1976.tb07689.x
更新日期:1976-09-01 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::1. The responses of rat isolated aortae to vasoconstrictor and vasodilator agents have been studied in 14-day streptozotocin-diabetic rats. The effects of treatment with the aldose reductase inhibitor, ponalrestat, on these responses have also been investigated. 2. Maximum contractile responses and aortic sensitivity ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1994.tb17028.x
更新日期:1994-10-01 00:00:00
abstract::We investigated the rate of penetration into and the intra-relationship between the serum, cerebrospinal fluid (CSF) and regional brain extracellular fluid (bECF) compartments following systemic administration of lamotrigine in rat. The serum pharmacokinetics were biphasic with an initial distribution phase, (half-lif...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0703337
更新日期:2000-05-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Inhibition of PDE5 improves synaptic plasticity and memory via enhancing cGMP expression, thus activating the cGMP/cAMP response element binding protein (CREB) signalling pathway. This study investigated the effects of a PDE5 inhibitor on scopolamine-induced cognitive dysfunction, using memory-re...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.14377
更新日期:2018-08-01 00:00:00
abstract::1. In this study we examined the effects of cortistatin, a putative endogenous ligand for somatostatin (SRIF) receptors, on the membrane properties of rat locus coeruleus (LC) neurones in vitro, by use of intracellular and whole cell patch clamp recording. We have compared the actions of cortistatin with those of SRIF...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0701541
更新日期:1997-12-01 00:00:00
abstract::1 4-Aminopyridine methiodide (4-APMI), a quaternary analogue of aminopyridine (4-AP), was tested for neuromuscular facilitatory actions on the chick biventer cervicis and frog sartorius nerve-muscle preparations. 2 In the chick, 4-APMI (10(-4) to 10(-2) M) augmented indirectly elicited twitches and reversed tubocurari...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1979.tb17333.x
更新日期:1979-01-01 00:00:00
abstract::1. It has recently been shown that both alpha(1)- and alpha(2)-adrenoceptors mediate vasoconstriction in the canine external carotid circulation. The present study set out to identify the specific subtypes (alpha(1A), alpha(1B) and alpha(1D) as well as alpha(2A), alpha(2B) and alpha(2C)) mediating the above response. ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0703915
更新日期:2001-03-01 00:00:00